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hsmusic-wiki - HSMusic - static wiki software cataloguing collaborative creation
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-rw-r--r--src/data/checks.js4
-rw-r--r--src/data/composite/things/album/index.js2
-rw-r--r--src/data/composite/things/album/withCoverArtDate.js (renamed from src/data/composite/wiki-data/withCoverArtDate.js)13
-rw-r--r--src/data/composite/things/artwork/index.js2
-rw-r--r--src/data/composite/things/artwork/withArtTags.js99
-rw-r--r--src/data/composite/things/artwork/withContentWarningArtTags.js27
-rw-r--r--src/data/composite/things/contribution/index.js2
-rw-r--r--src/data/composite/things/contribution/thingPropertyMatches.js45
-rw-r--r--src/data/composite/things/contribution/thingReferenceTypeMatches.js66
-rw-r--r--src/data/composite/wiki-data/exitWithoutArtwork.js45
-rw-r--r--src/data/composite/wiki-data/index.js3
-rw-r--r--src/data/composite/wiki-data/withHasArtwork.js (renamed from src/data/composite/things/album/withHasCoverArt.js)59
-rw-r--r--src/data/things/additional-file.js11
-rw-r--r--src/data/things/additional-name.js10
-rw-r--r--src/data/things/album.js522
-rw-r--r--src/data/things/art-tag.js37
-rw-r--r--src/data/things/artist.js117
-rw-r--r--src/data/things/artwork.js96
-rw-r--r--src/data/things/content.js48
-rw-r--r--src/data/things/contribution.js120
-rw-r--r--src/data/things/flash.js20
-rw-r--r--src/data/things/group.js67
-rw-r--r--src/data/things/homepage-layout.js42
-rw-r--r--src/data/things/language.js58
-rw-r--r--src/data/things/news-entry.js8
-rw-r--r--src/data/things/sorting-rule.js26
-rw-r--r--src/data/things/static-page.js10
-rw-r--r--src/data/things/track.js515
-rw-r--r--src/data/things/wiki-info.js10
-rw-r--r--src/data/yaml.js65
30 files changed, 1510 insertions, 639 deletions
diff --git a/src/data/checks.js b/src/data/checks.js
index afd2a04c..3fcb6d3b 100644
--- a/src/data/checks.js
+++ b/src/data/checks.js
@@ -192,6 +192,10 @@ export function filterReferenceErrors(wikiData, {
       directDescendantArtTags: 'artTag',
     }],
 
+    ['artworkData', {
+      referencedArtworks: '_artwork',
+    }],
+
     ['flashData', {
       commentary: '_content',
       creditingSources: '_content',
diff --git a/src/data/composite/things/album/index.js b/src/data/composite/things/album/index.js
index dfc6864f..de1d37c3 100644
--- a/src/data/composite/things/album/index.js
+++ b/src/data/composite/things/album/index.js
@@ -1,2 +1,2 @@
-export {default as withHasCoverArt} from './withHasCoverArt.js';
+export {default as withCoverArtDate} from './withCoverArtDate.js';
 export {default as withTracks} from './withTracks.js';
diff --git a/src/data/composite/wiki-data/withCoverArtDate.js b/src/data/composite/things/album/withCoverArtDate.js
index a114d5ff..978f566a 100644
--- a/src/data/composite/wiki-data/withCoverArtDate.js
+++ b/src/data/composite/things/album/withCoverArtDate.js
@@ -2,8 +2,7 @@ import {input, templateCompositeFrom} from '#composite';
 import {isDate} from '#validators';
 
 import {raiseOutputWithoutDependency} from '#composite/control-flow';
-
-import withResolvedContribs from './withResolvedContribs.js';
+import {withHasArtwork} from '#composite/wiki-data';
 
 export default templateCompositeFrom({
   annotation: `withCoverArtDate`,
@@ -19,14 +18,14 @@ export default templateCompositeFrom({
   outputs: ['#coverArtDate'],
 
   steps: () => [
-    withResolvedContribs({
-      from: 'coverArtistContribs',
-      date: input.value(null),
+    withHasArtwork({
+      contribs: 'coverArtistContribs',
+      artworks: 'coverArtworks',
     }),
 
     raiseOutputWithoutDependency({
-      dependency: '#resolvedContribs',
-      mode: input.value('empty'),
+      dependency: '#hasArtwork',
+      mode: input.value('falsy'),
       output: input.value({'#coverArtDate': null}),
     }),
 
diff --git a/src/data/composite/things/artwork/index.js b/src/data/composite/things/artwork/index.js
index 3693c10f..b5e5e167 100644
--- a/src/data/composite/things/artwork/index.js
+++ b/src/data/composite/things/artwork/index.js
@@ -1,5 +1,7 @@
+export {default as withArtTags} from './withArtTags.js';
 export {default as withAttachedArtwork} from './withAttachedArtwork.js';
 export {default as withContainingArtworkList} from './withContainingArtworkList.js';
+export {default as withContentWarningArtTags} from './withContentWarningArtTags.js';
 export {default as withContribsFromAttachedArtwork} from './withContribsFromAttachedArtwork.js';
 export {default as withDate} from './withDate.js';
 export {default as withPropertyFromAttachedArtwork} from './withPropertyFromAttachedArtwork.js';
diff --git a/src/data/composite/things/artwork/withArtTags.js b/src/data/composite/things/artwork/withArtTags.js
new file mode 100644
index 00000000..1fed3c31
--- /dev/null
+++ b/src/data/composite/things/artwork/withArtTags.js
@@ -0,0 +1,99 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency, withResultOfAvailabilityCheck}
+  from '#composite/control-flow';
+import {withPropertyFromObject} from '#composite/data';
+import {withResolvedReferenceList} from '#composite/wiki-data';
+import {soupyFind} from '#composite/wiki-properties';
+
+import withPropertyFromAttachedArtwork
+  from './withPropertyFromAttachedArtwork.js';
+
+export default templateCompositeFrom({
+  annotation: `withArtTags`,
+
+  inputs: {
+    from: input({
+      type: 'array',
+      acceptsNull: true,
+      defaultDependency: 'artTags',
+    }),
+  },
+
+  outputs: ['#artTags'],
+
+  steps: () => [
+    withResolvedReferenceList({
+      list: input('from'),
+      find: soupyFind.input('artTag'),
+    }),
+
+    withResultOfAvailabilityCheck({
+      from: '#resolvedReferenceList',
+      mode: input.value('empty'),
+    }),
+
+    {
+      dependencies: ['#availability', '#resolvedReferenceList'],
+      compute: (continuation, {
+        ['#availability']: availability,
+        ['#resolvedReferenceList']: resolvedReferenceList,
+      }) =>
+        (availability
+          ? continuation.raiseOutput({
+              '#artTags': resolvedReferenceList,
+            })
+          : continuation()),
+    },
+
+    withPropertyFromAttachedArtwork({
+      property: input.value('artTags'),
+    }),
+
+    withResultOfAvailabilityCheck({
+      from: '#attachedArtwork.artTags',
+      mode: input.value('empty'),
+    }),
+
+    {
+      dependencies: ['#availability', '#attachedArtwork.artTags'],
+      compute: (continuation, {
+        ['#availability']: availability,
+        ['#attachedArtwork.artTags']: attachedArtworkArtTags,
+      }) =>
+        (availability
+          ? continuation.raiseOutput({
+              '#artTags': attachedArtworkArtTags,
+            })
+          : continuation()),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: 'artTagsFromThingProperty',
+      output: input.value({'#artTags': []}),
+    }),
+
+    withPropertyFromObject({
+      object: 'thing',
+      property: 'artTagsFromThingProperty',
+    }).outputs({
+      ['#value']: '#thing.artTags',
+    }),
+
+    withResultOfAvailabilityCheck({
+      from: '#thing.artTags',
+      mode: input.value('empty'),
+    }),
+
+    {
+      dependencies: ['#availability', '#thing.artTags'],
+      compute: (continuation, {
+        ['#availability']: availability,
+        ['#thing.artTags']: thingArtTags,
+      }) =>
+        (availability
+          ? continuation({'#artTags': thingArtTags})
+          : continuation({'#artTags': []})),
+    },
+  ],
+});
diff --git a/src/data/composite/things/artwork/withContentWarningArtTags.js b/src/data/composite/things/artwork/withContentWarningArtTags.js
new file mode 100644
index 00000000..4c07e837
--- /dev/null
+++ b/src/data/composite/things/artwork/withContentWarningArtTags.js
@@ -0,0 +1,27 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {withFilteredList, withPropertyFromList} from '#composite/data';
+
+import withArtTags from './withArtTags.js';
+
+export default templateCompositeFrom({
+  annotation: `withContentWarningArtTags`,
+
+  outputs: ['#contentWarningArtTags'],
+
+  steps: () => [
+    withArtTags(),
+
+    withPropertyFromList({
+      list: '#artTags',
+      property: input.value('isContentWarning'),
+    }),
+
+    withFilteredList({
+      list: '#artTags',
+      filter: '#artTags.isContentWarning',
+    }).outputs({
+      '#filteredList': '#contentWarningArtTags',
+    }),
+  ],
+});
diff --git a/src/data/composite/things/contribution/index.js b/src/data/composite/things/contribution/index.js
index 9b22be2e..31d86b8b 100644
--- a/src/data/composite/things/contribution/index.js
+++ b/src/data/composite/things/contribution/index.js
@@ -1,6 +1,4 @@
 export {default as inheritFromContributionPresets} from './inheritFromContributionPresets.js';
-export {default as thingPropertyMatches} from './thingPropertyMatches.js';
-export {default as thingReferenceTypeMatches} from './thingReferenceTypeMatches.js';
 export {default as withContainingReverseContributionList} from './withContainingReverseContributionList.js';
 export {default as withContributionArtist} from './withContributionArtist.js';
 export {default as withContributionContext} from './withContributionContext.js';
diff --git a/src/data/composite/things/contribution/thingPropertyMatches.js b/src/data/composite/things/contribution/thingPropertyMatches.js
deleted file mode 100644
index a678c3f5..00000000
--- a/src/data/composite/things/contribution/thingPropertyMatches.js
+++ /dev/null
@@ -1,45 +0,0 @@
-import {input, templateCompositeFrom} from '#composite';
-
-import {exitWithoutDependency} from '#composite/control-flow';
-
-export default templateCompositeFrom({
-  annotation: `thingPropertyMatches`,
-
-  compose: false,
-
-  inputs: {
-    value: input({type: 'string'}),
-  },
-
-  steps: () => [
-    {
-      dependencies: ['thing', 'thingProperty'],
-
-      compute: (continuation, {thing, thingProperty}) =>
-        continuation({
-          ['#thingProperty']:
-            (thing.constructor[Symbol.for('Thing.referenceType')] === 'artwork'
-              ? thing.artistContribsFromThingProperty
-              : thingProperty),
-        }),
-    },
-
-    exitWithoutDependency({
-      dependency: '#thingProperty',
-      value: input.value(false),
-    }),
-
-    {
-      dependencies: [
-        '#thingProperty',
-        input('value'),
-      ],
-
-      compute: ({
-        ['#thingProperty']: thingProperty,
-        [input('value')]: value,
-      }) =>
-        thingProperty === value,
-    },
-  ],
-});
diff --git a/src/data/composite/things/contribution/thingReferenceTypeMatches.js b/src/data/composite/things/contribution/thingReferenceTypeMatches.js
deleted file mode 100644
index 4042e78f..00000000
--- a/src/data/composite/things/contribution/thingReferenceTypeMatches.js
+++ /dev/null
@@ -1,66 +0,0 @@
-import {input, templateCompositeFrom} from '#composite';
-
-import {exitWithoutDependency} from '#composite/control-flow';
-import {withPropertyFromObject} from '#composite/data';
-
-export default templateCompositeFrom({
-  annotation: `thingReferenceTypeMatches`,
-
-  compose: false,
-
-  inputs: {
-    value: input({type: 'string'}),
-  },
-
-  steps: () => [
-    exitWithoutDependency({
-      dependency: 'thing',
-      value: input.value(false),
-    }),
-
-    withPropertyFromObject({
-      object: 'thing',
-      property: input.value('constructor'),
-    }),
-
-    {
-      dependencies: [
-        '#thing.constructor',
-        input('value'),
-      ],
-
-      compute: (continuation, {
-        ['#thing.constructor']: constructor,
-        [input('value')]: value,
-      }) =>
-        (constructor[Symbol.for('Thing.referenceType')] === value
-          ? continuation.exit(true)
-       : constructor[Symbol.for('Thing.referenceType')] === 'artwork'
-          ? continuation()
-          : continuation.exit(false)),
-    },
-
-    withPropertyFromObject({
-      object: 'thing',
-      property: input.value('thing'),
-    }),
-
-    withPropertyFromObject({
-      object: '#thing.thing',
-      property: input.value('constructor'),
-    }),
-
-    {
-      dependencies: [
-        '#thing.thing.constructor',
-        input('value'),
-      ],
-
-      compute: ({
-        ['#thing.thing.constructor']: constructor,
-        [input('value')]: value,
-      }) =>
-        constructor[Symbol.for('Thing.referenceType')] === value,
-    },
-  ],
-});
diff --git a/src/data/composite/wiki-data/exitWithoutArtwork.js b/src/data/composite/wiki-data/exitWithoutArtwork.js
new file mode 100644
index 00000000..8e799fda
--- /dev/null
+++ b/src/data/composite/wiki-data/exitWithoutArtwork.js
@@ -0,0 +1,45 @@
+import {input, templateCompositeFrom} from '#composite';
+import {isContributionList, isThing, strictArrayOf} from '#validators';
+
+import {exitWithoutDependency} from '#composite/control-flow';
+
+import withHasArtwork from './withHasArtwork.js';
+
+export default templateCompositeFrom({
+  annotation: `exitWithoutArtwork`,
+
+  inputs: {
+    contribs: input({
+      validate: isContributionList,
+      defaultValue: null,
+    }),
+
+    artwork: input({
+      validate: isThing,
+      defaultValue: null,
+    }),
+
+    artworks: input({
+      validate: strictArrayOf(isThing),
+      defaultValue: null,
+    }),
+
+    value: input({
+      defaultValue: null,
+    }),
+  },
+
+  steps: () => [
+    withHasArtwork({
+      contribs: input('contribs'),
+      artwork: input('artwork'),
+      artworks: input('artworks'),
+    }),
+
+    exitWithoutDependency({
+      dependency: '#hasArtwork',
+      mode: input.value('falsy'),
+      value: input('value'),
+    }),
+  ],
+});
diff --git a/src/data/composite/wiki-data/index.js b/src/data/composite/wiki-data/index.js
index 38afc2ac..3206575b 100644
--- a/src/data/composite/wiki-data/index.js
+++ b/src/data/composite/wiki-data/index.js
@@ -5,6 +5,7 @@
 //
 
 export {default as exitWithoutContribs} from './exitWithoutContribs.js';
+export {default as exitWithoutArtwork} from './exitWithoutArtwork.js';
 export {default as gobbleSoupyFind} from './gobbleSoupyFind.js';
 export {default as gobbleSoupyReverse} from './gobbleSoupyReverse.js';
 export {default as inputNotFoundMode} from './inputNotFoundMode.js';
@@ -16,8 +17,8 @@ export {default as withClonedThings} from './withClonedThings.js';
 export {default as withConstitutedArtwork} from './withConstitutedArtwork.js';
 export {default as withContentNodes} from './withContentNodes.js';
 export {default as withContributionListSums} from './withContributionListSums.js';
-export {default as withCoverArtDate} from './withCoverArtDate.js';
 export {default as withDirectory} from './withDirectory.js';
+export {default as withHasArtwork} from './withHasArtwork.js';
 export {default as withRecontextualizedContributionList} from './withRecontextualizedContributionList.js';
 export {default as withRedatedContributionList} from './withRedatedContributionList.js';
 export {default as withResolvedAnnotatedReferenceList} from './withResolvedAnnotatedReferenceList.js';
diff --git a/src/data/composite/things/album/withHasCoverArt.js b/src/data/composite/wiki-data/withHasArtwork.js
index fd3f2894..9c22f439 100644
--- a/src/data/composite/things/album/withHasCoverArt.js
+++ b/src/data/composite/wiki-data/withHasArtwork.js
@@ -1,7 +1,5 @@
-// TODO: This shouldn't be coded as an Album-specific thing,
-// or even really to do with cover artworks in particular, either.
-
 import {input, templateCompositeFrom} from '#composite';
+import {isContributionList, isThing, strictArrayOf} from '#validators';
 
 import {raiseOutputWithoutDependency, withResultOfAvailabilityCheck}
   from '#composite/control-flow';
@@ -9,13 +7,30 @@ import {fillMissingListItems, withFlattenedList, withPropertyFromList}
   from '#composite/data';
 
 export default templateCompositeFrom({
-  annotation: 'withHasCoverArt',
+  annotation: 'withHasArtwork',
+
+  inputs: {
+    contribs: input({
+      validate: isContributionList,
+      defaultValue: null,
+    }),
+
+    artwork: input({
+      validate: isThing,
+      defaultValue: null,
+    }),
+
+    artworks: input({
+      validate: strictArrayOf(isThing),
+      defaultValue: null,
+    }),
+  },
 
-  outputs: ['#hasCoverArt'],
+  outputs: ['#hasArtwork'],
 
   steps: () => [
     withResultOfAvailabilityCheck({
-      from: 'coverArtistContribs',
+      from: input('contribs'),
       mode: input.value('empty'),
     }),
 
@@ -26,19 +41,37 @@ export default templateCompositeFrom({
       }) =>
         (availability
           ? continuation.raiseOutput({
-              ['#hasCoverArt']: true,
+              ['#hasArtwork']: true,
             })
           : continuation()),
     },
 
+    {
+      dependencies: [input('artwork'), input('artworks')],
+      compute: (continuation, {
+        [input('artwork')]: artwork,
+        [input('artworks')]: artworks,
+      }) =>
+        continuation({
+          ['#artworks']:
+            (artwork && artworks
+              ? [artwork, ...artworks]
+           : artwork
+              ? [artwork]
+           : artworks
+              ? artworks
+              : []),
+        }),
+    },
+
     raiseOutputWithoutDependency({
-      dependency: 'coverArtworks',
+      dependency: '#artworks',
       mode: input.value('empty'),
-      output: input.value({'#hasCoverArt': false}),
+      output: input.value({'#hasArtwork': false}),
     }),
 
     withPropertyFromList({
-      list: 'coverArtworks',
+      list: '#artworks',
       property: input.value('artistContribs'),
       internal: input.value(true),
     }),
@@ -46,19 +79,19 @@ export default templateCompositeFrom({
     // Since we're getting the update value for each artwork's artistContribs,
     // it may not be set at all, and in that case won't be exposing as [].
     fillMissingListItems({
-      list: '#coverArtworks.artistContribs',
+      list: '#artworks.artistContribs',
       fill: input.value([]),
     }),
 
     withFlattenedList({
-      list: '#coverArtworks.artistContribs',
+      list: '#artworks.artistContribs',
     }),
 
     withResultOfAvailabilityCheck({
       from: '#flattenedList',
       mode: input.value('empty'),
     }).outputs({
-      '#availability': '#hasCoverArt',
+      '#availability': '#hasArtwork',
     }),
   ],
 });
diff --git a/src/data/things/additional-file.js b/src/data/things/additional-file.js
index 398d0af5..b15f62e0 100644
--- a/src/data/things/additional-file.js
+++ b/src/data/things/additional-file.js
@@ -2,10 +2,9 @@ import {input} from '#composite';
 import Thing from '#thing';
 import {isString, validateArrayItems} from '#validators';
 
-import {contentString, simpleString, thing} from '#composite/wiki-properties';
-
 import {exposeConstant, exposeUpdateValueOrContinue}
   from '#composite/control-flow';
+import {contentString, simpleString, thing} from '#composite/wiki-properties';
 
 export class AdditionalFile extends Thing {
   static [Thing.getPropertyDescriptors] = () => ({
@@ -26,6 +25,14 @@ export class AdditionalFile extends Thing {
         value: input.value([]),
       }),
     ],
+
+    // Expose only
+
+    isAdditionalFile: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = {
diff --git a/src/data/things/additional-name.js b/src/data/things/additional-name.js
index 4c23f291..99f3ee46 100644
--- a/src/data/things/additional-name.js
+++ b/src/data/things/additional-name.js
@@ -1,5 +1,7 @@
+import {input} from '#composite';
 import Thing from '#thing';
 
+import {exposeConstant} from '#composite/control-flow';
 import {contentString, thing} from '#composite/wiki-properties';
 
 export class AdditionalName extends Thing {
@@ -10,6 +12,14 @@ export class AdditionalName extends Thing {
 
     name: contentString(),
     annotation: contentString(),
+
+    // Expose only
+
+    isAdditionalName: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = {
diff --git a/src/data/things/album.js b/src/data/things/album.js
index af42c6fa..427c5d7f 100644
--- a/src/data/things/album.js
+++ b/src/data/things/album.js
@@ -10,7 +10,8 @@ import {traverse} from '#node-utils';
 import {sortAlbumsTracksChronologically, sortChronologically} from '#sort';
 import {empty} from '#sugar';
 import Thing from '#thing';
-import {isColor, isDate, isDirectory, isNumber} from '#validators';
+import {is, isColor, isContributionList, isDate, isDirectory, isNumber}
+  from '#validators';
 
 import {
   parseAdditionalFiles,
@@ -25,12 +26,22 @@ import {
   parseWallpaperParts,
 } from '#yaml';
 
-import {exitWithoutDependency, exposeDependency, exposeUpdateValueOrContinue}
-  from '#composite/control-flow';
 import {withPropertyFromObject} from '#composite/data';
 
-import {exitWithoutContribs, withDirectory, withCoverArtDate}
-  from '#composite/wiki-data';
+import {
+  exitWithoutDependency,
+  exposeConstant,
+  exposeDependency,
+  exposeDependencyOrContinue,
+  exposeUpdateValueOrContinue,
+} from '#composite/control-flow';
+
+import {
+  exitWithoutArtwork,
+  withDirectory,
+  withHasArtwork,
+  withResolvedContribs,
+} from '#composite/wiki-data';
 
 import {
   color,
@@ -58,7 +69,7 @@ import {
   wikiData,
 } from '#composite/wiki-properties';
 
-import {withHasCoverArt, withTracks} from '#composite/things/album';
+import {withCoverArtDate, withTracks} from '#composite/things/album';
 import {withAlbum, withContinueCountingFrom, withStartCountingFrom}
   from '#composite/things/track-section';
 
@@ -76,7 +87,13 @@ export class Album extends Thing {
     TrackSection,
     WikiInfo,
   }) => ({
-    // Update & expose
+    // > Update & expose - Internal relationships
+
+    trackSections: thingList({
+      class: input.value(TrackSection),
+    }),
+
+    // > Update & expose - Identifying metadata
 
     name: name('Unnamed Album'),
     directory: directory(),
@@ -97,20 +114,105 @@ export class Album extends Thing {
     alwaysReferenceTracksByDirectory: flag(false),
     suffixTrackDirectories: flag(false),
 
-    color: color(),
-    urls: urls(),
+    style: [
+      exposeUpdateValueOrContinue({
+        validate: input.value(is(...[
+          'album',
+          'single',
+        ])),
+      }),
 
-    additionalNames: thingList({
-      class: input.value(AdditionalName),
-    }),
+      exposeConstant({
+        value: input.value('album'),
+      }),
+    ],
 
     bandcampAlbumIdentifier: simpleString(),
     bandcampArtworkIdentifier: simpleString(),
 
+    additionalNames: thingList({
+      class: input.value(AdditionalName),
+    }),
+
     date: simpleDate(),
-    trackArtDate: simpleDate(),
     dateAddedToWiki: simpleDate(),
 
+    // > Update & expose - Credits and contributors
+
+    artistContribs: contributionList({
+      date: 'date',
+      artistProperty: input.value('albumArtistContributions'),
+    }),
+
+    trackArtistContribs: [
+      withResolvedContribs({
+        from: input.updateValue({validate: isContributionList}),
+        thingProperty: input.thisProperty(),
+        artistProperty: input.value('albumTrackArtistContributions'),
+        date: 'date',
+      }).outputs({
+        '#resolvedContribs': '#trackArtistContribs',
+      }),
+
+      exposeDependencyOrContinue({
+        dependency: '#trackArtistContribs',
+        mode: input.value('empty'),
+      }),
+
+      withResolvedContribs({
+        from: 'artistContribs',
+        thingProperty: input.thisProperty(),
+        artistProperty: input.value('albumTrackArtistContributions'),
+        date: 'date',
+      }).outputs({
+        '#resolvedContribs': '#trackArtistContribs',
+      }),
+
+      exposeDependency({dependency: '#trackArtistContribs'}),
+    ],
+
+    // > Update & expose - General configuration
+
+    countTracksInArtistTotals: flag(true),
+
+    hasTrackNumbers: flag(true),
+    isListedOnHomepage: flag(true),
+    isListedInGalleries: flag(true),
+
+    hideDuration: flag(false),
+
+    // > Update & expose - General metadata
+
+    color: color(),
+
+    urls: urls(),
+
+    // > Update & expose - Artworks
+
+    coverArtworks: [
+      // This works, lol, because this array describes `expose.transform` for
+      // the coverArtworks property, and compositions generally access the
+      // update value, not what's exposed by property access out in the open.
+      // There's no recursion going on here.
+      exitWithoutArtwork({
+        contribs: 'coverArtistContribs',
+        artworks: 'coverArtworks',
+        value: input.value([]),
+      }),
+
+      constitutibleArtworkList.fromYAMLFieldSpec
+        .call(this, 'Cover Artwork'),
+    ],
+
+    coverArtistContribs: [
+      withCoverArtDate(),
+
+      contributionList({
+        date: '#coverArtDate',
+        artistProperty: input.value('albumCoverArtistContributions'),
+      }),
+    ],
+
     coverArtDate: [
       withCoverArtDate({
         from: input.updateValue({
@@ -122,52 +224,61 @@ export class Album extends Thing {
     ],
 
     coverArtFileExtension: [
-      exitWithoutContribs({contribs: 'coverArtistContribs'}),
+      exitWithoutArtwork({
+        contribs: 'coverArtistContribs',
+        artworks: 'coverArtworks',
+      }),
+
       fileExtension('jpg'),
     ],
 
-    trackCoverArtFileExtension: fileExtension('jpg'),
+    coverArtDimensions: [
+      exitWithoutArtwork({
+        contribs: 'coverArtistContribs',
+        artworks: 'coverArtworks',
+      }),
 
-    wallpaperFileExtension: [
-      exitWithoutContribs({contribs: 'wallpaperArtistContribs'}),
-      fileExtension('jpg'),
+      dimensions(),
     ],
 
-    bannerFileExtension: [
-      exitWithoutContribs({contribs: 'bannerArtistContribs'}),
-      fileExtension('jpg'),
-    ],
+    artTags: [
+      exitWithoutArtwork({
+        contribs: 'coverArtistContribs',
+        artworks: 'coverArtworks',
+        value: input.value([]),
+      }),
 
-    wallpaperStyle: [
-      exitWithoutContribs({contribs: 'wallpaperArtistContribs'}),
-      simpleString(),
+      referenceList({
+        class: input.value(ArtTag),
+        find: soupyFind.input('artTag'),
+      }),
     ],
 
-    wallpaperParts: [
-      exitWithoutContribs({
-        contribs: 'wallpaperArtistContribs',
+    referencedArtworks: [
+      exitWithoutArtwork({
+        contribs: 'coverArtistContribs',
+        artworks: 'coverArtworks',
         value: input.value([]),
       }),
 
-      wallpaperParts(),
+      referencedArtworkList(),
     ],
 
-    bannerStyle: [
-      exitWithoutContribs({contribs: 'bannerArtistContribs'}),
-      simpleString(),
-    ],
+    trackCoverArtistContribs: contributionList({
+      // May be null, indicating cover art was added for tracks on the date
+      // each track specifies, or else the track's own release date.
+      date: 'trackArtDate',
 
-    coverArtDimensions: [
-      exitWithoutContribs({contribs: 'coverArtistContribs'}),
-      dimensions(),
-    ],
+      // This is the "correct" value, but it gets overwritten - with the same
+      // value - regardless.
+      artistProperty: input.value('trackCoverArtistContributions'),
+    }),
 
-    trackDimensions: dimensions(),
+    trackArtDate: simpleDate(),
 
-    bannerDimensions: [
-      exitWithoutContribs({contribs: 'bannerArtistContribs'}),
-      dimensions(),
-    ],
+    trackCoverArtFileExtension: fileExtension('jpg'),
+
+    trackDimensions: dimensions(),
 
     wallpaperArtwork: [
       exitWithoutDependency({
@@ -180,119 +291,115 @@ export class Album extends Thing {
         .call(this, 'Wallpaper Artwork'),
     ],
 
-    bannerArtwork: [
-      exitWithoutDependency({
-        dependency: 'bannerArtistContribs',
-        mode: input.value('empty'),
-        value: input.value(null),
-      }),
+    wallpaperArtistContribs: [
+      withCoverArtDate(),
 
-      constitutibleArtwork.fromYAMLFieldSpec
-        .call(this, 'Banner Artwork'),
+      contributionList({
+        date: '#coverArtDate',
+        artistProperty: input.value('albumWallpaperArtistContributions'),
+      }),
     ],
 
-    coverArtworks: [
-      withHasCoverArt(),
-
-      exitWithoutDependency({
-        dependency: '#hasCoverArt',
-        mode: input.value('falsy'),
-        value: input.value([]),
+    wallpaperFileExtension: [
+      exitWithoutArtwork({
+        contribs: 'wallpaperArtistContribs',
+        artwork: 'wallpaperArtwork',
       }),
 
-      constitutibleArtworkList.fromYAMLFieldSpec
-        .call(this, 'Cover Artwork'),
+      fileExtension('jpg'),
     ],
 
-    hasTrackNumbers: flag(true),
-    isListedOnHomepage: flag(true),
-    isListedInGalleries: flag(true),
+    wallpaperStyle: [
+      exitWithoutArtwork({
+        contribs: 'wallpaperArtistContribs',
+        artwork: 'wallpaperArtwork',
+      }),
 
-    commentary: thingList({
-      class: input.value(CommentaryEntry),
-    }),
+      simpleString(),
+    ],
 
-    creditingSources: thingList({
-      class: input.value(CreditingSourcesEntry),
-    }),
+    wallpaperParts: [
+      // kinda nonsensical or at least unlikely lol, but y'know
+      exitWithoutArtwork({
+        contribs: 'wallpaperArtistContribs',
+        artwork: 'wallpaperArtwork',
+        value: input.value([]),
+      }),
 
-    additionalFiles: thingList({
-      class: input.value(AdditionalFile),
-    }),
+      wallpaperParts(),
+    ],
 
-    trackSections: thingList({
-      class: input.value(TrackSection),
-    }),
+    bannerArtwork: [
+      exitWithoutDependency({
+        dependency: 'bannerArtistContribs',
+        mode: input.value('empty'),
+        value: input.value(null),
+      }),
 
-    artistContribs: contributionList({
-      date: 'date',
-      artistProperty: input.value('albumArtistContributions'),
-    }),
+      constitutibleArtwork.fromYAMLFieldSpec
+        .call(this, 'Banner Artwork'),
+    ],
 
-    coverArtistContribs: [
+    bannerArtistContribs: [
       withCoverArtDate(),
 
       contributionList({
         date: '#coverArtDate',
-        artistProperty: input.value('albumCoverArtistContributions'),
+        artistProperty: input.value('albumBannerArtistContributions'),
       }),
     ],
 
-    trackCoverArtistContribs: contributionList({
-      // May be null, indicating cover art was added for tracks on the date
-      // each track specifies, or else the track's own release date.
-      date: 'trackArtDate',
-
-      // This is the "correct" value, but it gets overwritten - with the same
-      // value - regardless.
-      artistProperty: input.value('trackCoverArtistContributions'),
-    }),
+    bannerFileExtension: [
+      exitWithoutArtwork({
+        contribs: 'bannerArtistContribs',
+        artwork: 'bannerArtwork',
+      }),
 
-    wallpaperArtistContribs: [
-      withCoverArtDate(),
+      fileExtension('jpg'),
+    ],
 
-      contributionList({
-        date: '#coverArtDate',
-        artistProperty: input.value('albumWallpaperArtistContributions'),
+    bannerDimensions: [
+      exitWithoutArtwork({
+        contribs: 'bannerArtistContribs',
+        artwork: 'bannerArtwork',
       }),
-    ],
 
-    bannerArtistContribs: [
-      withCoverArtDate(),
+      dimensions(),
+    ],
 
-      contributionList({
-        date: '#coverArtDate',
-        artistProperty: input.value('albumBannerArtistContributions'),
+    bannerStyle: [
+      exitWithoutArtwork({
+        contribs: 'bannerArtistContribs',
+        artwork: 'bannerArtwork',
       }),
+
+      simpleString(),
     ],
 
+    // > Update & expose - Groups
+
     groups: referenceList({
       class: input.value(Group),
       find: soupyFind.input('group'),
     }),
 
-    artTags: [
-      exitWithoutContribs({
-        contribs: 'coverArtistContribs',
-        value: input.value([]),
-      }),
+    // > Update & expose - Content entries
 
-      referenceList({
-        class: input.value(ArtTag),
-        find: soupyFind.input('artTag'),
-      }),
-    ],
+    commentary: thingList({
+      class: input.value(CommentaryEntry),
+    }),
 
-    referencedArtworks: [
-      exitWithoutContribs({
-        contribs: 'coverArtistContribs',
-        value: input.value([]),
-      }),
+    creditingSources: thingList({
+      class: input.value(CreditingSourcesEntry),
+    }),
 
-      referencedArtworkList(),
-    ],
+    // > Update & expose - Additional files
 
-    // Update only
+    additionalFiles: thingList({
+      class: input.value(AdditionalFile),
+    }),
+
+    // > Update only
 
     find: soupyFind(),
     reverse: soupyReverse(),
@@ -307,13 +414,23 @@ export class Album extends Thing {
       class: input.value(WikiInfo),
     }),
 
-    // Expose only
+    // > Expose only
+
+    isAlbum: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
 
     commentatorArtists: commentatorArtists(),
 
     hasCoverArt: [
-      withHasCoverArt(),
-      exposeDependency({dependency: '#hasCoverArt'}),
+      withHasArtwork({
+        contribs: 'coverArtistContribs',
+        artworks: 'coverArtworks',
+      }),
+
+      exposeDependency({dependency: '#hasArtwork'}),
     ],
 
     hasWallpaperArt: contribsPresent({contribs: 'wallpaperArtistContribs'}),
@@ -457,6 +574,9 @@ export class Album extends Thing {
     albumArtistContributionsBy:
       soupyReverse.contributionsBy('albumData', 'artistContribs'),
 
+    albumTrackArtistContributionsBy:
+      soupyReverse.contributionsBy('albumData', 'trackArtistContribs'),
+
     albumCoverArtistContributionsBy:
       soupyReverse.artworkContributionsBy('albumData', 'coverArtworks'),
 
@@ -476,21 +596,15 @@ export class Album extends Thing {
 
   static [Thing.yamlDocumentSpec] = {
     fields: {
-      'Album': {property: 'name'},
+      // Identifying metadata
 
+      'Album': {property: 'name'},
       'Directory': {property: 'directory'},
       'Directory Suffix': {property: 'directorySuffix'},
       'Suffix Track Directories': {property: 'suffixTrackDirectories'},
-
       'Always Reference By Directory': {property: 'alwaysReferenceByDirectory'},
-      'Always Reference Tracks By Directory': {
-        property: 'alwaysReferenceTracksByDirectory',
-      },
-
-      'Additional Names': {
-        property: 'additionalNames',
-        transform: parseAdditionalNames,
-      },
+      'Always Reference Tracks By Directory': {property: 'alwaysReferenceTracksByDirectory'},
+      'Style': {property: 'style'},
 
       'Bandcamp Album ID': {
         property: 'bandcampAlbumIdentifier',
@@ -502,18 +616,53 @@ export class Album extends Thing {
         transform: String,
       },
 
+      'Additional Names': {
+        property: 'additionalNames',
+        transform: parseAdditionalNames,
+      },
+
       'Date': {
         property: 'date',
         transform: parseDate,
       },
 
-      'Color': {property: 'color'},
-      'URLs': {property: 'urls'},
+      'Date Added': {
+        property: 'dateAddedToWiki',
+        transform: parseDate,
+      },
+
+      // Credits and contributors
+
+      'Artists': {
+        property: 'artistContribs',
+        transform: parseContributors,
+      },
+
+      'Track Artists': {
+        property: 'trackArtistContribs',
+        transform: parseContributors,
+      },
+
+      // General configuration
+
+      'Count Tracks In Artist Totals': {property: 'countTracksInArtistTotals'},
 
       'Has Track Numbers': {property: 'hasTrackNumbers'},
       'Listed on Homepage': {property: 'isListedOnHomepage'},
       'Listed in Galleries': {property: 'isListedInGalleries'},
 
+      'Hide Duration': {property: 'hideDuration'},
+
+      // General metadata
+
+      'Color': {property: 'color'},
+
+      'URLs': {property: 'urls'},
+
+      // Artworks
+      //  (Note - this YAML section is deliberately ordered differently
+      //   than the corresponding property descriptors.)
+
       'Cover Artwork': {
         property: 'coverArtworks',
         transform:
@@ -557,27 +706,29 @@ export class Album extends Thing {
           }),
       },
 
+      'Cover Artists': {
+        property: 'coverArtistContribs',
+        transform: parseContributors,
+      },
+
       'Cover Art Date': {
         property: 'coverArtDate',
         transform: parseDate,
       },
 
-      'Default Track Cover Art Date': {
-        property: 'trackArtDate',
-        transform: parseDate,
+      'Cover Art Dimensions': {
+        property: 'coverArtDimensions',
+        transform: parseDimensions,
       },
 
-      'Date Added': {
-        property: 'dateAddedToWiki',
-        transform: parseDate,
+      'Default Track Cover Artists': {
+        property: 'trackCoverArtistContribs',
+        transform: parseContributors,
       },
 
-      'Cover Art File Extension': {property: 'coverArtFileExtension'},
-      'Track Art File Extension': {property: 'trackCoverArtFileExtension'},
-
-      'Cover Art Dimensions': {
-        property: 'coverArtDimensions',
-        transform: parseDimensions,
+      'Default Track Cover Art Date': {
+        property: 'trackArtDate',
+        transform: parseDate,
       },
 
       'Default Track Dimensions': {
@@ -590,8 +741,6 @@ export class Album extends Thing {
         transform: parseContributors,
       },
 
-      'Wallpaper File Extension': {property: 'wallpaperFileExtension'},
-
       'Wallpaper Style': {property: 'wallpaperStyle'},
 
       'Wallpaper Parts': {
@@ -604,14 +753,31 @@ export class Album extends Thing {
         transform: parseContributors,
       },
 
-      'Banner Style': {property: 'bannerStyle'},
-      'Banner File Extension': {property: 'bannerFileExtension'},
-
       'Banner Dimensions': {
         property: 'bannerDimensions',
         transform: parseDimensions,
       },
 
+      'Banner Style': {property: 'bannerStyle'},
+
+      'Cover Art File Extension': {property: 'coverArtFileExtension'},
+      'Track Art File Extension': {property: 'trackCoverArtFileExtension'},
+      'Wallpaper File Extension': {property: 'wallpaperFileExtension'},
+      'Banner File Extension': {property: 'bannerFileExtension'},
+
+      'Art Tags': {property: 'artTags'},
+
+      'Referenced Artworks': {
+        property: 'referencedArtworks',
+        transform: parseAnnotatedReferences,
+      },
+
+      // Groups
+
+      'Groups': {property: 'groups'},
+
+      // Content entries
+
       'Commentary': {
         property: 'commentary',
         transform: parseCommentary,
@@ -622,40 +788,40 @@ export class Album extends Thing {
         transform: parseCreditingSources,
       },
 
+      // Additional files
+
       'Additional Files': {
         property: 'additionalFiles',
         transform: parseAdditionalFiles,
       },
 
-      'Referenced Artworks': {
-        property: 'referencedArtworks',
-        transform: parseAnnotatedReferences,
-      },
+      // Shenanigans
 
       'Franchises': {ignore: true},
+      'Review Points': {ignore: true},
+    },
 
-      'Artists': {
-        property: 'artistContribs',
-        transform: parseContributors,
-      },
-
-      'Cover Artists': {
-        property: 'coverArtistContribs',
-        transform: parseContributors,
-      },
+    invalidFieldCombinations: [
+      {message: `Move commentary on singles to the track`, fields: [
+        ['Style', 'single'],
+        'Commentary',
+      ]},
 
-      'Default Track Cover Artists': {
-        property: 'trackCoverArtistContribs',
-        transform: parseContributors,
-      },
+      {message: `Move crediting sources on singles to the track`, fields: [
+        ['Style', 'single'],
+        'Crediting Sources',
+      ]},
 
-      'Groups': {property: 'groups'},
-      'Art Tags': {property: 'artTags'},
+      {message: `Move referencing sources on singles to the track`, fields: [
+        ['Style', 'single'],
+        'Referencing Sources',
+      ]},
 
-      'Review Points': {ignore: true},
-    },
+      {message: `Move additional names on singles to the track`, fields: [
+        ['Style', 'single'],
+        'Additional Names',
+      ]},
 
-    invalidFieldCombinations: [
       {message: `Specify one wallpaper style or multiple wallpaper parts, not both`, fields: [
         'Wallpaper Parts',
         'Wallpaper Style',
@@ -835,6 +1001,12 @@ export class Album extends Thing {
       artwork.fileExtension,
     ];
   }
+
+  // As of writing, albums don't even have a `duration` property...
+  // so this function will never be called... but the message stands...
+  countOwnContributionInDurationTotals(_contrib) {
+    return false;
+  }
 }
 
 export class TrackSection extends Thing {
@@ -892,6 +1064,12 @@ export class TrackSection extends Thing {
 
     // Expose only
 
+    isTrackSection: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     directory: [
       withAlbum(),
 
diff --git a/src/data/things/art-tag.js b/src/data/things/art-tag.js
index 518f616b..fff724cb 100644
--- a/src/data/things/art-tag.js
+++ b/src/data/things/art-tag.js
@@ -1,14 +1,23 @@
+export const DATA_ART_TAGS_DIRECTORY = 'art-tags';
 export const ART_TAG_DATA_FILE = 'tags.yaml';
 
+import {readFile} from 'node:fs/promises';
+import * as path from 'node:path';
+
 import {input} from '#composite';
+import {traverse} from '#node-utils';
 import {sortAlphabetically} from '#sort';
 import Thing from '#thing';
 import {unique} from '#sugar';
 import {isName} from '#validators';
 import {parseAdditionalNames, parseAnnotatedReferences} from '#yaml';
 
-import {exitWithoutDependency, exposeDependency, exposeUpdateValueOrContinue}
-  from '#composite/control-flow';
+import {
+  exitWithoutDependency,
+  exposeConstant,
+  exposeDependency,
+  exposeUpdateValueOrContinue,
+} from '#composite/control-flow';
 
 import {
   annotatedReferenceList,
@@ -79,6 +88,12 @@ export class ArtTag extends Thing {
 
     // Expose only
 
+    isArtTag: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     descriptionShort: [
       exitWithoutDependency({
         dependency: 'description',
@@ -174,13 +189,25 @@ export class ArtTag extends Thing {
   };
 
   static [Thing.getYamlLoadingSpec] = ({
-    documentModes: {allInOne},
+    documentModes: {allTogether},
     thingConstructors: {ArtTag},
   }) => ({
     title: `Process art tags file`,
-    file: ART_TAG_DATA_FILE,
 
-    documentMode: allInOne,
+    files: dataPath =>
+      Promise.allSettled([
+        readFile(path.join(dataPath, ART_TAG_DATA_FILE))
+          .then(() => [ART_TAG_DATA_FILE]),
+
+        traverse(path.join(dataPath, DATA_ART_TAGS_DIRECTORY), {
+          filterFile: name => path.extname(name) === '.yaml',
+          prefixPath: DATA_ART_TAGS_DIRECTORY,
+        }),
+      ]).then(results => results
+          .filter(({status}) => status === 'fulfilled')
+          .flatMap(({value}) => value)),
+
+    documentMode: allTogether,
     documentThing: ArtTag,
 
     save: (results) => ({artTagData: results}),
diff --git a/src/data/things/artist.js b/src/data/things/artist.js
index 5b67051c..2905d893 100644
--- a/src/data/things/artist.js
+++ b/src/data/things/artist.js
@@ -5,14 +5,21 @@ import {inspect} from 'node:util';
 import CacheableObject from '#cacheable-object';
 import {colors} from '#cli';
 import {input} from '#composite';
-import {sortAlphabetically} from '#sort';
 import {stitchArrays} from '#sugar';
 import Thing from '#thing';
 import {isName, validateArrayItems} from '#validators';
 import {getKebabCase} from '#wiki-data';
 import {parseArtwork} from '#yaml';
 
-import {exitWithoutDependency} from '#composite/control-flow';
+import {
+  sortAlbumsTracksChronologically,
+  sortArtworksChronologically,
+  sortAlphabetically,
+  sortContributionsChronologically,
+} from '#sort';
+
+import {exitWithoutDependency, exposeConstant} from '#composite/control-flow';
+import {withReverseReferenceList} from '#composite/wiki-data';
 
 import {
   constitutibleArtwork,
@@ -76,6 +83,12 @@ export class Artist extends Thing {
 
     // Expose only
 
+    isArtist: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     trackArtistContributions: reverseReferenceList({
       reverse: soupyReverse.input('trackArtistContributionsBy'),
     }),
@@ -96,6 +109,10 @@ export class Artist extends Thing {
       reverse: soupyReverse.input('albumArtistContributionsBy'),
     }),
 
+    albumTrackArtistContributions: reverseReferenceList({
+      reverse: soupyReverse.input('albumTrackArtistContributionsBy'),
+    }),
+
     albumCoverArtistContributions: reverseReferenceList({
       reverse: soupyReverse.input('albumCoverArtistContributionsBy'),
     }),
@@ -124,6 +141,102 @@ export class Artist extends Thing {
       reverse: soupyReverse.input('groupsCloselyLinkedTo'),
     }),
 
+    musicContributions: [
+      withReverseReferenceList({
+        reverse: soupyReverse.input('trackArtistContributionsBy'),
+      }).outputs({
+        '#reverseReferenceList': '#trackArtistContribs',
+      }),
+
+      withReverseReferenceList({
+        reverse: soupyReverse.input('trackContributorContributionsBy'),
+      }).outputs({
+        '#reverseReferenceList': '#trackContributorContribs',
+      }),
+
+      {
+        dependencies: [
+          '#trackArtistContribs',
+          '#trackContributorContribs',
+        ],
+
+        compute: (continuation, {
+          ['#trackArtistContribs']: trackArtistContribs,
+          ['#trackContributorContribs']: trackContributorContribs,
+        }) => continuation({
+          ['#contributions']: [
+            ...trackArtistContribs,
+            ...trackContributorContribs,
+          ],
+        }),
+      },
+
+      {
+        dependencies: ['#contributions'],
+        compute: ({'#contributions': contributions}) =>
+          sortContributionsChronologically(
+            contributions,
+            sortAlbumsTracksChronologically),
+      },
+    ],
+
+    artworkContributions: [
+      withReverseReferenceList({
+        reverse: soupyReverse.input('trackCoverArtistContributionsBy'),
+      }).outputs({
+        '#reverseReferenceList': '#trackCoverArtistContribs',
+      }),
+
+      withReverseReferenceList({
+        reverse: soupyReverse.input('albumCoverArtistContributionsBy'),
+      }).outputs({
+        '#reverseReferenceList': '#albumCoverArtistContribs',
+      }),
+
+      withReverseReferenceList({
+        reverse: soupyReverse.input('albumWallpaperArtistContributionsBy'),
+      }).outputs({
+        '#reverseReferenceList': '#albumWallpaperArtistContribs',
+      }),
+
+      withReverseReferenceList({
+        reverse: soupyReverse.input('albumBannerArtistContributionsBy'),
+      }).outputs({
+        '#reverseReferenceList': '#albumBannerArtistContribs',
+      }),
+
+      {
+        dependencies: [
+          '#trackCoverArtistContribs',
+          '#albumCoverArtistContribs',
+          '#albumWallpaperArtistContribs',
+          '#albumBannerArtistContribs',
+        ],
+
+        compute: (continuation, {
+          ['#trackCoverArtistContribs']: trackCoverArtistContribs,
+          ['#albumCoverArtistContribs']: albumCoverArtistContribs,
+          ['#albumWallpaperArtistContribs']: albumWallpaperArtistContribs,
+          ['#albumBannerArtistContribs']: albumBannerArtistContribs,
+        }) => continuation({
+          ['#contributions']: [
+            ...trackCoverArtistContribs,
+            ...albumCoverArtistContribs,
+            ...albumWallpaperArtistContribs,
+            ...albumBannerArtistContribs,
+          ],
+        }),
+      },
+
+      {
+        dependencies: ['#contributions'],
+        compute: ({'#contributions': contributions}) =>
+          sortContributionsChronologically(
+            contributions,
+            sortArtworksChronologically),
+      },
+    ],
+
     totalDuration: artistTotalDuration(),
   });
 
diff --git a/src/data/things/artwork.js b/src/data/things/artwork.js
index 3cf380a0..c54bcced 100644
--- a/src/data/things/artwork.js
+++ b/src/data/things/artwork.js
@@ -25,7 +25,7 @@ import {
   parseDimensions,
 } from '#yaml';
 
-import {withPropertyFromObject} from '#composite/data';
+import {withPropertyFromList, withPropertyFromObject} from '#composite/data';
 
 import {
   exitWithoutDependency,
@@ -55,8 +55,10 @@ import {
 } from '#composite/wiki-properties';
 
 import {
+  withArtTags,
   withAttachedArtwork,
   withContainingArtworkList,
+  withContentWarningArtTags,
   withContribsFromAttachedArtwork,
   withPropertyFromAttachedArtwork,
   withDate,
@@ -170,6 +172,7 @@ export class Artwork extends Thing {
       withResolvedContribs({
         from: input.updateValue({validate: isContributionList}),
         date: '#date',
+        thingProperty: input.thisProperty(),
         artistProperty: 'artistContribsArtistProperty',
       }),
 
@@ -208,47 +211,16 @@ export class Artwork extends Thing {
     artTagsFromThingProperty: simpleString(),
 
     artTags: [
-      withResolvedReferenceList({
-        list: input.updateValue({
+      withArtTags({
+        from: input.updateValue({
           validate:
             validateReferenceList(ArtTag[Thing.referenceType]),
         }),
-
-        find: soupyFind.input('artTag'),
-      }),
-
-      exposeDependencyOrContinue({
-        dependency: '#resolvedReferenceList',
-        mode: input.value('empty'),
-      }),
-
-      withPropertyFromAttachedArtwork({
-        property: input.value('artTags'),
-      }),
-
-      exposeDependencyOrContinue({
-        dependency: '#attachedArtwork.artTags',
-      }),
-
-      exitWithoutDependency({
-        dependency: 'artTagsFromThingProperty',
-        value: input.value([]),
       }),
 
-      withPropertyFromObject({
-        object: 'thing',
-        property: 'artTagsFromThingProperty',
-      }).outputs({
-        ['#value']: '#artTags',
-      }),
-
-      exposeDependencyOrContinue({
+      exposeDependency({
         dependency: '#artTags',
       }),
-
-      exposeConstant({
-        value: input.value([]),
-      }),
     ],
 
     referencedArtworksFromThingProperty: simpleString(),
@@ -322,6 +294,12 @@ export class Artwork extends Thing {
 
     // Expose only
 
+    isArtwork: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     referencedByArtworks: reverseReferenceList({
       reverse: soupyReverse.input('artworksWhichReference'),
     }),
@@ -370,6 +348,42 @@ export class Artwork extends Thing {
     attachingArtworks: reverseReferenceList({
       reverse: soupyReverse.input('artworksWhichAttach'),
     }),
+
+    groups: [
+      withPropertyFromObject({
+        object: 'thing',
+        property: input.value('groups'),
+      }),
+
+      exposeDependencyOrContinue({
+        dependency: '#thing.groups',
+      }),
+
+      exposeConstant({
+        value: input.value([]),
+      }),
+    ],
+
+    contentWarningArtTags: [
+      withContentWarningArtTags(),
+
+      exposeDependency({
+        dependency: '#contentWarningArtTags',
+      }),
+    ],
+
+    contentWarnings: [
+      withContentWarningArtTags(),
+
+      withPropertyFromList({
+        list: '#contentWarningArtTags',
+        property: input.value('name'),
+      }),
+
+      exposeDependency({
+        dependency: '#contentWarningArtTags.name',
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = {
@@ -456,6 +470,18 @@ export class Artwork extends Thing {
     return this.thing.getOwnArtworkPath(this);
   }
 
+  countOwnContributionInContributionTotals(contrib) {
+    if (this.attachAbove) {
+      return false;
+    }
+
+    if (contrib.annotation?.startsWith('edits for wiki')) {
+      return false;
+    }
+
+    return true;
+  }
+
   [inspect.custom](depth, options, inspect) {
     const parts = [];
 
diff --git a/src/data/things/content.js b/src/data/things/content.js
index e380780c..d2cf32dc 100644
--- a/src/data/things/content.js
+++ b/src/data/things/content.js
@@ -50,6 +50,10 @@ export class ContentEntry extends Thing {
     },
 
     accessKind: [
+      exitWithoutDependency({
+        dependency: 'accessDate',
+      }),
+
       exposeUpdateValueOrContinue({
         validate: input.value(
           is(...[
@@ -73,7 +77,7 @@ export class ContentEntry extends Thing {
       },
 
       exposeConstant({
-        value: input.value(null),
+        value: input.value('accessed'),
       }),
     ],
 
@@ -105,6 +109,12 @@ export class ContentEntry extends Thing {
 
     // Expose only
 
+    isContentEntry: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     annotationParts: [
       withAnnotationParts({
         mode: input.value('strings'),
@@ -147,6 +157,12 @@ export class CommentaryEntry extends ContentEntry {
   static [Thing.getPropertyDescriptors] = () => ({
     // Expose only
 
+    isCommentaryEntry: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     isWikiEditorCommentary: hasAnnotationPart({
       part: input.value('wiki editor'),
     }),
@@ -161,6 +177,12 @@ export class LyricsEntry extends ContentEntry {
 
     // Expose only
 
+    isLyricsEntry: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     isWikiLyrics: hasAnnotationPart({
       part: input.value('wiki lyrics'),
     }),
@@ -196,6 +218,26 @@ export class LyricsEntry extends ContentEntry {
   });
 }
 
-export class CreditingSourcesEntry extends ContentEntry {}
+export class CreditingSourcesEntry extends ContentEntry {
+  static [Thing.getPropertyDescriptors] = () => ({
+    // Expose only
+
+    isCreditingSourcesEntry: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+  });
+}
 
-export class ReferencingSourcesEntry extends ContentEntry {}
+export class ReferencingSourcesEntry extends ContentEntry {
+  static [Thing.getPropertyDescriptors] = () => ({
+    // Expose only
+
+    isReferencingSourceEntry: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+  });
+}
diff --git a/src/data/things/contribution.js b/src/data/things/contribution.js
index b3655eb8..006aeec0 100644
--- a/src/data/things/contribution.js
+++ b/src/data/things/contribution.js
@@ -5,12 +5,20 @@ import {colors} from '#cli';
 import {input} from '#composite';
 import {empty} from '#sugar';
 import Thing from '#thing';
-import {isStringNonEmpty, isThing, validateReference} from '#validators';
+import {isBoolean, isStringNonEmpty, isThing, validateReference}
+  from '#validators';
 
-import {exitWithoutDependency, exposeDependency} from '#composite/control-flow';
 import {flag, simpleDate, soupyFind} from '#composite/wiki-properties';
 
 import {
+  exitWithoutDependency,
+  exposeConstant,
+  exposeDependency,
+  exposeDependencyOrContinue,
+  exposeUpdateValueOrContinue,
+} from '#composite/control-flow';
+
+import {
   withFilteredList,
   withNearbyItemFromList,
   withPropertyFromList,
@@ -19,8 +27,6 @@ import {
 
 import {
   inheritFromContributionPresets,
-  thingPropertyMatches,
-  thingReferenceTypeMatches,
   withContainingReverseContributionList,
   withContributionArtist,
   withContributionContext,
@@ -70,7 +76,26 @@ export class Contribution extends Thing {
         property: input.thisProperty(),
       }),
 
-      flag(true),
+      exposeUpdateValueOrContinue({
+        validate: input.value(isBoolean),
+      }),
+
+      {
+        dependencies: ['thing', input.myself()],
+        compute: (continuation, {
+          ['thing']: thing,
+          [input.myself()]: contribution,
+        }) =>
+          (thing.countOwnContributionInContributionTotals?.(contribution)
+            ? true
+         : thing.countOwnContributionInContributionTotals
+            ? false
+            : continuation()),
+      },
+
+      exposeConstant({
+        value: input.value(true),
+      }),
     ],
 
     countInDurationTotals: [
@@ -78,7 +103,37 @@ export class Contribution extends Thing {
         property: input.thisProperty(),
       }),
 
-      flag(true),
+      exposeUpdateValueOrContinue({
+        validate: input.value(isBoolean),
+      }),
+
+      withPropertyFromObject({
+        object: 'thing',
+        property: input.value('duration'),
+      }),
+
+      exitWithoutDependency({
+        dependency: '#thing.duration',
+        mode: input.value('falsy'),
+        value: input.value(false),
+      }),
+
+      {
+        dependencies: ['thing', input.myself()],
+        compute: (continuation, {
+          ['thing']: thing,
+          [input.myself()]: contribution,
+        }) =>
+          (thing.countOwnContributionInDurationTotals?.(contribution)
+            ? true
+         : thing.countOwnContributionInDurationTotals
+            ? false
+            : continuation()),
+      },
+
+      exposeConstant({
+        value: input.value(true),
+      }),
     ],
 
     // Update only
@@ -87,6 +142,12 @@ export class Contribution extends Thing {
 
     // Expose only
 
+    isContribution: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     context: [
       withContributionContext(),
 
@@ -167,38 +228,6 @@ export class Contribution extends Thing {
       }),
     ],
 
-    isArtistContribution: thingPropertyMatches({
-      value: input.value('artistContribs'),
-    }),
-
-    isContributorContribution: thingPropertyMatches({
-      value: input.value('contributorContribs'),
-    }),
-
-    isCoverArtistContribution: thingPropertyMatches({
-      value: input.value('coverArtistContribs'),
-    }),
-
-    isBannerArtistContribution: thingPropertyMatches({
-      value: input.value('bannerArtistContribs'),
-    }),
-
-    isWallpaperArtistContribution: thingPropertyMatches({
-      value: input.value('wallpaperArtistContribs'),
-    }),
-
-    isForTrack: thingReferenceTypeMatches({
-      value: input.value('track'),
-    }),
-
-    isForAlbum: thingReferenceTypeMatches({
-      value: input.value('album'),
-    }),
-
-    isForFlash: thingReferenceTypeMatches({
-      value: input.value('flash'),
-    }),
-
     previousBySameArtist: [
       withContainingReverseContributionList().outputs({
         '#containingReverseContributionList': '#list',
@@ -238,6 +267,21 @@ export class Contribution extends Thing {
         dependency: '#nearbyItem',
       }),
     ],
+
+    groups: [
+      withPropertyFromObject({
+        object: 'thing',
+        property: input.value('groups'),
+      }),
+
+      exposeDependencyOrContinue({
+        dependency: '#thing.groups',
+      }),
+
+      exposeConstant({
+        value: input.value([]),
+      }),
+    ],
   });
 
   [inspect.custom](depth, options, inspect) {
diff --git a/src/data/things/flash.js b/src/data/things/flash.js
index 160221f0..73b22746 100644
--- a/src/data/things/flash.js
+++ b/src/data/things/flash.js
@@ -149,6 +149,12 @@ export class Flash extends Thing {
 
     // Expose only
 
+    isFlash: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     commentatorArtists: commentatorArtists(),
 
     act: [
@@ -317,6 +323,12 @@ export class FlashAct extends Thing {
 
     // Expose only
 
+    isFlashAct: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     side: [
       withFlashSide(),
       exposeDependency({dependency: '#flashSide'}),
@@ -372,6 +384,14 @@ export class FlashSide extends Thing {
     // Update only
 
     find: soupyFind(),
+
+    // Expose only
+
+    isFlashSide: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = {
diff --git a/src/data/things/group.js b/src/data/things/group.js
index 0262a3a5..0935dc93 100644
--- a/src/data/things/group.js
+++ b/src/data/things/group.js
@@ -5,17 +5,28 @@ import {inspect} from 'node:util';
 import {colors} from '#cli';
 import {input} from '#composite';
 import Thing from '#thing';
-import {is} from '#validators';
+import {is, isBoolean} from '#validators';
 import {parseAnnotatedReferences, parseSerieses} from '#yaml';
 
+import {withPropertyFromObject} from '#composite/data';
+import {withUniqueReferencingThing} from '#composite/wiki-data';
+
+import {
+  exposeConstant,
+  exposeDependencyOrContinue,
+  exposeUpdateValueOrContinue,
+} from '#composite/control-flow';
+
 import {
   annotatedReferenceList,
   color,
   contentString,
   directory,
+  flag,
   name,
   referenceList,
   soupyFind,
+  soupyReverse,
   thing,
   thingList,
   urls,
@@ -30,6 +41,33 @@ export class Group extends Thing {
     name: name('Unnamed Group'),
     directory: directory(),
 
+    excludeFromGalleryTabs: [
+      exposeUpdateValueOrContinue({
+        validate: input.value(isBoolean),
+      }),
+
+      withUniqueReferencingThing({
+        reverse: soupyReverse.input('groupCategoriesWhichInclude'),
+      }).outputs({
+        '#uniqueReferencingThing': '#category',
+      }),
+
+      withPropertyFromObject({
+        object: '#category',
+        property: input.value('excludeGroupsFromGalleryTabs'),
+      }),
+
+      exposeDependencyOrContinue({
+        dependency: '#category.excludeGroupsFromGalleryTabs',
+      }),
+
+      exposeConstant({
+        value: input.value(false),
+      }),
+    ],
+
+    divideAlbumsByStyle: flag(false),
+
     description: contentString(),
 
     urls: urls(),
@@ -54,10 +92,16 @@ export class Group extends Thing {
     // Update only
 
     find: soupyFind(),
-    reverse: soupyFind(),
+    reverse: soupyReverse(),
 
     // Expose only
 
+    isGroup: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     descriptionShort: {
       flags: {expose: true},
 
@@ -133,6 +177,10 @@ export class Group extends Thing {
     fields: {
       'Group': {property: 'name'},
       'Directory': {property: 'directory'},
+
+      'Exclude From Gallery Tabs': {property: 'excludeFromGalleryTabs'},
+      'Divide Albums By Style': {property: 'divideAlbumsByStyle'},
+
       'Description': {property: 'description'},
       'URLs': {property: 'urls'},
 
@@ -217,6 +265,8 @@ export class GroupCategory extends Thing {
     name: name('Unnamed Group Category'),
     directory: directory(),
 
+    excludeGroupsFromGalleryTabs: flag(false),
+
     color: color(),
 
     groups: referenceList({
@@ -227,6 +277,14 @@ export class GroupCategory extends Thing {
     // Update only
 
     find: soupyFind(),
+
+    // Expose only
+
+    isGroupCategory: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.reverseSpecs] = {
@@ -241,7 +299,12 @@ export class GroupCategory extends Thing {
   static [Thing.yamlDocumentSpec] = {
     fields: {
       'Category': {property: 'name'},
+
       'Color': {property: 'color'},
+
+      'Exclude Groups From Gallery Tabs': {
+        property: 'excludeGroupsFromGalleryTabs',
+      },
     },
   };
 }
diff --git a/src/data/things/homepage-layout.js b/src/data/things/homepage-layout.js
index 3a11c287..2456ca95 100644
--- a/src/data/things/homepage-layout.js
+++ b/src/data/things/homepage-layout.js
@@ -17,7 +17,7 @@ import {
   validateReference,
 } from '#validators';
 
-import {exposeDependency} from '#composite/control-flow';
+import {exposeConstant, exposeDependency} from '#composite/control-flow';
 import {withResolvedReference} from '#composite/wiki-data';
 
 import {
@@ -47,6 +47,14 @@ export class HomepageLayout extends Thing {
     sections: thingList({
       class: input.value(HomepageLayoutSection),
     }),
+
+    // Expose only
+
+    isHomepageLayout: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = {
@@ -156,6 +164,14 @@ export class HomepageLayoutSection extends Thing {
     rows: thingList({
       class: input.value(HomepageLayoutRow),
     }),
+
+    // Expose only
+
+    isHomepageLayoutSection: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = {
@@ -182,6 +198,12 @@ export class HomepageLayoutRow extends Thing {
 
     // Expose only
 
+    isHomepageLayoutRow: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     type: {
       flags: {expose: true},
 
@@ -233,6 +255,12 @@ export class HomepageLayoutActionsRow extends HomepageLayoutRow {
 
     // Expose only
 
+    isHomepageLayoutActionsRow: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     type: {
       flags: {expose: true},
       expose: {compute: () => 'actions'},
@@ -261,6 +289,12 @@ export class HomepageLayoutAlbumCarouselRow extends HomepageLayoutRow {
 
     // Expose only
 
+    isHomepageLayoutAlbumCarouselRow: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     type: {
       flags: {expose: true},
       expose: {compute: () => 'album carousel'},
@@ -321,6 +355,12 @@ export class HomepageLayoutAlbumGridRow extends HomepageLayoutRow {
 
     // Expose only
 
+    isHomepageLayoutAlbumGridRow: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     type: {
       flags: {expose: true},
       expose: {compute: () => 'album grid'},
diff --git a/src/data/things/language.js b/src/data/things/language.js
index b0124c10..88e8d996 100644
--- a/src/data/things/language.js
+++ b/src/data/things/language.js
@@ -1,8 +1,9 @@
-import { Temporal, toTemporalInstant } from '@js-temporal/polyfill';
+import {Temporal, toTemporalInstant} from '@js-temporal/polyfill';
 
 import {withAggregate} from '#aggregate';
 import CacheableObject from '#cacheable-object';
 import {logWarn} from '#cli';
+import {input} from '#composite';
 import * as html from '#html';
 import {empty} from '#sugar';
 import {isLanguageCode} from '#validators';
@@ -16,6 +17,7 @@ import {
   isExternalLinkStyle,
 } from '#external-links';
 
+import {exposeConstant} from '#composite/control-flow';
 import {externalFunction, flag, name} from '#composite/wiki-properties';
 
 export const languageOptionRegex = /{(?<name>[A-Z0-9_]+)}/g;
@@ -127,6 +129,12 @@ export class Language extends Thing {
 
     // Expose only
 
+    isLanguage: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     onlyIfOptions: {
       flags: {expose: true},
       expose: {
@@ -204,6 +212,10 @@ export class Language extends Thing {
   }
 
   formatString(...args) {
+    if (typeof args.at(-1) === 'function') {
+      throw new Error(`Passed function - did you mean language.encapsulate() instead?`);
+    }
+
     const hasOptions =
       typeof args.at(-1) === 'object' &&
       args.at(-1) !== null;
@@ -310,7 +322,7 @@ export class Language extends Thing {
           return undefined;
         }
 
-        return optionValue;
+        return this.sanitize(optionValue);
       },
     });
 
@@ -375,26 +387,16 @@ export class Language extends Thing {
 
       partInProgress += template.slice(lastIndex, match.index);
 
-      // Sanitize string arguments in particular. These are taken to come from
-      // (raw) data and may include special characters that aren't meant to be
-      // rendered as HTML markup.
-      const sanitizedInsertion =
-        this.#sanitizeValueForInsertion(insertion);
-
-      if (typeof sanitizedInsertion === 'string') {
-        // Join consecutive strings together.
-        partInProgress += sanitizedInsertion;
-      } else if (
-        sanitizedInsertion instanceof html.Tag &&
-        sanitizedInsertion.contentOnly
-      ) {
-        // Collapse string-only tag contents onto the current string part.
-        partInProgress += sanitizedInsertion.toString();
-      } else {
-        // Push the string part in progress, then the insertion as-is.
-        outputParts.push(partInProgress);
-        outputParts.push(sanitizedInsertion);
-        partInProgress = '';
+      for (const insertionItem of html.smush(insertion).content) {
+        if (typeof insertionItem === 'string') {
+          // Join consecutive strings together.
+          partInProgress += insertionItem;
+        } else {
+          // Push the string part in progress, then the insertion as-is.
+          outputParts.push(partInProgress);
+          outputParts.push(insertionItem);
+          partInProgress = '';
+        }
       }
 
       lastIndex = match.index + match[0].length;
@@ -867,14 +869,14 @@ export class Language extends Thing {
 
   typicallyLowerCase(string) {
     // Utter nonsense implementation, so this only works on strings,
-    // not actual HTML content, and will loudly disrespect *intentful*
+    // not actual HTML content, and may rudely disrespect *intentful*
     // capitalization of whatever goes into it.
 
-    if (typeof string === 'string') {
-      return string[0].toLowerCase() + string.slice(1).toLowerCase();
-    } else {
-      return string;
-    }
+    if (typeof string !== 'string') return string;
+    if (string.length <= 1) return string;
+    if (/^\S+?[A-Z]/.test(string)) return string;
+
+    return string[0].toLowerCase() + string.slice(1);
   }
 
   // Utility function to quickly provide a useful string key
diff --git a/src/data/things/news-entry.js b/src/data/things/news-entry.js
index 43d1638e..28289f53 100644
--- a/src/data/things/news-entry.js
+++ b/src/data/things/news-entry.js
@@ -1,9 +1,11 @@
 export const NEWS_DATA_FILE = 'news.yaml';
 
+import {input} from '#composite';
 import {sortChronologically} from '#sort';
 import Thing from '#thing';
 import {parseDate} from '#yaml';
 
+import {exposeConstant} from '#composite/control-flow';
 import {contentString, directory, name, simpleDate}
   from '#composite/wiki-properties';
 
@@ -22,6 +24,12 @@ export class NewsEntry extends Thing {
 
     // Expose only
 
+    isNewsEntry: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
+
     contentShort: {
       flags: {expose: true},
 
diff --git a/src/data/things/sorting-rule.js b/src/data/things/sorting-rule.js
index ccc4ad89..808a0085 100644
--- a/src/data/things/sorting-rule.js
+++ b/src/data/things/sorting-rule.js
@@ -3,6 +3,7 @@ export const SORTING_RULE_DATA_FILE = 'sorting-rules.yaml';
 import {readFile, writeFile} from 'node:fs/promises';
 import * as path from 'node:path';
 
+import {input} from '#composite';
 import {chunkByProperties, compareArrays, unique} from '#sugar';
 import Thing from '#thing';
 import {isObject, isStringNonEmpty, anyOf, strictArrayOf} from '#validators';
@@ -21,6 +22,7 @@ import {
   reorderDocumentsInYAMLSourceText,
 } from '#yaml';
 
+import {exposeConstant} from '#composite/control-flow';
 import {flag} from '#composite/wiki-properties';
 
 function isSelectFollowingEntry(value) {
@@ -46,6 +48,14 @@ export class SortingRule extends Thing {
       flags: {update: true, expose: true},
       update: {validate: isStringNonEmpty},
     },
+
+    // Expose only
+
+    isSortingRule: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = {
@@ -118,6 +128,14 @@ export class ThingSortingRule extends SortingRule {
         validate: strictArrayOf(isStringNonEmpty),
       },
     },
+
+    // Expose only
+
+    isThingSortingRule: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = Thing.extendDocumentSpec(SortingRule, {
@@ -217,6 +235,14 @@ export class DocumentSortingRule extends ThingSortingRule {
       flags: {update: true, expose: true},
       update: {validate: isStringNonEmpty},
     },
+
+    // Expose only
+
+    isDocumentSortingRule: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = Thing.extendDocumentSpec(ThingSortingRule, {
diff --git a/src/data/things/static-page.js b/src/data/things/static-page.js
index 52a09c31..28167df2 100644
--- a/src/data/things/static-page.js
+++ b/src/data/things/static-page.js
@@ -2,11 +2,13 @@ export const DATA_STATIC_PAGE_DIRECTORY = 'static-page';
 
 import * as path from 'node:path';
 
+import {input} from '#composite';
 import {traverse} from '#node-utils';
 import {sortAlphabetically} from '#sort';
 import Thing from '#thing';
 import {isName} from '#validators';
 
+import {exposeConstant} from '#composite/control-flow';
 import {contentString, directory, flag, name, simpleString}
   from '#composite/wiki-properties';
 
@@ -36,6 +38,14 @@ export class StaticPage extends Thing {
     content: contentString(),
 
     absoluteLinks: flag(),
+
+    // Expose only
+
+    isStaticPage: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.findSpecs] = {
diff --git a/src/data/things/track.js b/src/data/things/track.js
index 8419f8ba..18faebc3 100644
--- a/src/data/things/track.js
+++ b/src/data/things/track.js
@@ -25,6 +25,7 @@ import {
 import {withPropertyFromObject} from '#composite/data';
 
 import {
+  exitWithoutDependency,
   exposeConstant,
   exposeDependency,
   exposeDependencyOrContinue,
@@ -95,7 +96,13 @@ export class Track extends Thing {
     ReferencingSourcesEntry,
     WikiInfo,
   }) => ({
-    // Update & expose
+    // > Update & expose - Internal relationships
+
+    album: thing({
+      class: input.value(Album),
+    }),
+
+    // > Update & expose - Identifying metadata
 
     name: name('Unnamed Track'),
 
@@ -129,20 +136,93 @@ export class Track extends Thing {
       })
     ],
 
-    album: thing({
-      class: input.value(Album),
+    alwaysReferenceByDirectory: [
+      withAlwaysReferenceByDirectory(),
+      exposeDependency({dependency: '#alwaysReferenceByDirectory'}),
+    ],
+
+    mainReleaseTrack: singleReference({
+      class: input.value(Track),
+      find: soupyFind.input('track'),
     }),
 
+    bandcampTrackIdentifier: simpleString(),
+    bandcampArtworkIdentifier: simpleString(),
+
     additionalNames: thingList({
       class: input.value(AdditionalName),
     }),
 
-    bandcampTrackIdentifier: simpleString(),
-    bandcampArtworkIdentifier: simpleString(),
+    dateFirstReleased: simpleDate(),
+
+    // > Update & expose - Credits and contributors
+
+    artistContribs: [
+      inheritContributionListFromMainRelease(),
+
+      withDate(),
+
+      withResolvedContribs({
+        from: input.updateValue({validate: isContributionList}),
+        thingProperty: input.thisProperty(),
+        artistProperty: input.value('trackArtistContributions'),
+        date: '#date',
+      }).outputs({
+        '#resolvedContribs': '#artistContribs',
+      }),
+
+      exposeDependencyOrContinue({
+        dependency: '#artistContribs',
+        mode: input.value('empty'),
+      }),
+
+      withPropertyFromAlbum({
+        property: input.value('trackArtistContribs'),
+      }),
+
+      withRecontextualizedContributionList({
+        list: '#album.trackArtistContribs',
+        artistProperty: input.value('trackArtistContributions'),
+      }),
+
+      withRedatedContributionList({
+        list: '#album.trackArtistContribs',
+        date: '#date',
+      }),
+
+      exposeDependency({dependency: '#album.trackArtistContribs'}),
+    ],
+
+    contributorContribs: [
+      inheritContributionListFromMainRelease(),
+
+      withDate(),
+
+      contributionList({
+        date: '#date',
+        artistProperty: input.value('trackContributorContributions'),
+      }),
+    ],
+
+    // > Update & expose - General configuration
+
+    countInArtistTotals: [
+      exposeUpdateValueOrContinue({
+        validate: input.value(isBoolean),
+      }),
+
+      withPropertyFromAlbum({
+        property: input.value('countTracksInArtistTotals'),
+      }),
+
+      exposeDependency({dependency: '#album.countTracksInArtistTotals'}),
+    ],
+
+    disableUniqueCoverArt: flag(),
+
+    // > Update & expose - General metadata
 
     duration: duration(),
-    urls: urls(),
-    dateFirstReleased: simpleDate(),
 
     color: [
       exposeUpdateValueOrContinue({
@@ -165,37 +245,27 @@ export class Track extends Thing {
       exposeDependency({dependency: '#album.color'}),
     ],
 
-    alwaysReferenceByDirectory: [
-      withAlwaysReferenceByDirectory(),
-      exposeDependency({dependency: '#alwaysReferenceByDirectory'}),
-    ],
-
-    // Disables presenting the track as though it has its own unique artwork.
-    // This flag should only be used in select circumstances, i.e. to override
-    // an album's trackCoverArtists. This flag supercedes that property, as well
-    // as the track's own coverArtists.
-    disableUniqueCoverArt: flag(),
-
-    // File extension for track's corresponding media file. This represents the
-    // track's unique cover artwork, if any, and does not inherit the extension
-    // of the album's main artwork. It does inherit trackCoverArtFileExtension,
-    // if present on the album.
-    coverArtFileExtension: [
-      exitWithoutUniqueCoverArt(),
+    urls: urls(),
 
-      exposeUpdateValueOrContinue({
-        validate: input.value(isFileExtension),
-      }),
+    // > Update & expose - Artworks
 
-      withPropertyFromAlbum({
-        property: input.value('trackCoverArtFileExtension'),
+    trackArtworks: [
+      exitWithoutUniqueCoverArt({
+        value: input.value([]),
       }),
 
-      exposeDependencyOrContinue({dependency: '#album.trackCoverArtFileExtension'}),
+      constitutibleArtworkList.fromYAMLFieldSpec
+        .call(this, 'Track Artwork'),
+    ],
 
-      exposeConstant({
-        value: input.value('jpg'),
+    coverArtistContribs: [
+      withCoverArtistContribs({
+        from: input.updateValue({
+          validate: isContributionList,
+        }),
       }),
+
+      exposeDependency({dependency: '#coverArtistContribs'}),
     ],
 
     coverArtDate: [
@@ -208,117 +278,59 @@ export class Track extends Thing {
       exposeDependency({dependency: '#trackArtDate'}),
     ],
 
-    coverArtDimensions: [
+    coverArtFileExtension: [
       exitWithoutUniqueCoverArt(),
 
-      exposeUpdateValueOrContinue(),
+      exposeUpdateValueOrContinue({
+        validate: input.value(isFileExtension),
+      }),
 
       withPropertyFromAlbum({
-        property: input.value('trackDimensions'),
+        property: input.value('trackCoverArtFileExtension'),
       }),
 
-      exposeDependencyOrContinue({dependency: '#album.trackDimensions'}),
-
-      dimensions(),
-    ],
-
-    commentary: thingList({
-      class: input.value(CommentaryEntry),
-    }),
-
-    creditingSources: thingList({
-      class: input.value(CreditingSourcesEntry),
-    }),
-
-    referencingSources: thingList({
-      class: input.value(ReferencingSourcesEntry),
-    }),
-
-    lyrics: [
-      // TODO: Inherited lyrics are literally the same objects, so of course
-      // their .thing properties aren't going to point back to this one, and
-      // certainly couldn't be recontextualized...
-      inheritFromMainRelease(),
+      exposeDependencyOrContinue({dependency: '#album.trackCoverArtFileExtension'}),
 
-      thingList({
-        class: input.value(LyricsEntry),
+      exposeConstant({
+        value: input.value('jpg'),
       }),
     ],
 
-    additionalFiles: thingList({
-      class: input.value(AdditionalFile),
-    }),
-
-    sheetMusicFiles: thingList({
-      class: input.value(AdditionalFile),
-    }),
-
-    midiProjectFiles: thingList({
-      class: input.value(AdditionalFile),
-    }),
-
-    mainReleaseTrack: singleReference({
-      class: input.value(Track),
-      find: soupyFind.input('track'),
-    }),
-
-    artistContribs: [
-      inheritContributionListFromMainRelease(),
-
-      withDate(),
-
-      withResolvedContribs({
-        from: input.updateValue({validate: isContributionList}),
-        thingProperty: input.thisProperty(),
-        artistProperty: input.value('trackArtistContributions'),
-        date: '#date',
-      }).outputs({
-        '#resolvedContribs': '#artistContribs',
-      }),
+    coverArtDimensions: [
+      exitWithoutUniqueCoverArt(),
 
-      exposeDependencyOrContinue({
-        dependency: '#artistContribs',
-        mode: input.value('empty'),
-      }),
+      exposeUpdateValueOrContinue(),
 
       withPropertyFromAlbum({
-        property: input.value('artistContribs'),
-      }),
-
-      withRecontextualizedContributionList({
-        list: '#album.artistContribs',
-        artistProperty: input.value('trackArtistContributions'),
+        property: input.value('trackDimensions'),
       }),
 
-      withRedatedContributionList({
-        list: '#album.artistContribs',
-        date: '#date',
-      }),
+      exposeDependencyOrContinue({dependency: '#album.trackDimensions'}),
 
-      exposeDependency({dependency: '#album.artistContribs'}),
+      dimensions(),
     ],
 
-    contributorContribs: [
-      inheritContributionListFromMainRelease(),
-
-      withDate(),
+    artTags: [
+      exitWithoutUniqueCoverArt({
+        value: input.value([]),
+      }),
 
-      contributionList({
-        date: '#date',
-        artistProperty: input.value('trackContributorContributions'),
+      referenceList({
+        class: input.value(ArtTag),
+        find: soupyFind.input('artTag'),
       }),
     ],
 
-    coverArtistContribs: [
-      withCoverArtistContribs({
-        from: input.updateValue({
-          validate: isContributionList,
-        }),
+    referencedArtworks: [
+      exitWithoutUniqueCoverArt({
+        value: input.value([]),
       }),
 
-      exposeDependency({dependency: '#coverArtistContribs'}),
+      referencedArtworkList(),
     ],
 
+    // > Update & expose - Referenced tracks
+
     referencedTracks: [
       inheritFromMainRelease({
         notFoundValue: input.value([]),
@@ -341,35 +353,46 @@ export class Track extends Thing {
       }),
     ],
 
-    trackArtworks: [
-      exitWithoutUniqueCoverArt({
-        value: input.value([]),
-      }),
+    // > Update & expose - Additional files
 
-      constitutibleArtworkList.fromYAMLFieldSpec
-        .call(this, 'Track Artwork'),
-    ],
+    additionalFiles: thingList({
+      class: input.value(AdditionalFile),
+    }),
 
-    artTags: [
-      exitWithoutUniqueCoverArt({
-        value: input.value([]),
-      }),
+    sheetMusicFiles: thingList({
+      class: input.value(AdditionalFile),
+    }),
 
-      referenceList({
-        class: input.value(ArtTag),
-        find: soupyFind.input('artTag'),
+    midiProjectFiles: thingList({
+      class: input.value(AdditionalFile),
+    }),
+
+    // > Update & expose - Content entries
+
+    lyrics: [
+      // TODO: Inherited lyrics are literally the same objects, so of course
+      // their .thing properties aren't going to point back to this one, and
+      // certainly couldn't be recontextualized...
+      inheritFromMainRelease(),
+
+      thingList({
+        class: input.value(LyricsEntry),
       }),
     ],
 
-    referencedArtworks: [
-      exitWithoutUniqueCoverArt({
-        value: input.value([]),
-      }),
+    commentary: thingList({
+      class: input.value(CommentaryEntry),
+    }),
 
-      referencedArtworkList(),
-    ],
+    creditingSources: thingList({
+      class: input.value(CreditingSourcesEntry),
+    }),
+
+    referencingSources: thingList({
+      class: input.value(ReferencingSourcesEntry),
+    }),
 
-    // Update only
+    // > Update only
 
     find: soupyFind(),
     reverse: soupyReverse(),
@@ -389,7 +412,13 @@ export class Track extends Thing {
       class: input.value(WikiInfo),
     }),
 
-    // Expose only
+    // > Expose only
+
+    isTrack: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
 
     commentatorArtists: commentatorArtists(),
 
@@ -441,6 +470,34 @@ export class Track extends Thing {
       exposeDependency({dependency: '#otherReleases'}),
     ],
 
+    commentaryFromMainRelease: [
+      withMainRelease(),
+
+      exitWithoutDependency({
+        dependency: '#mainRelease',
+        value: input.value([]),
+      }),
+
+      withPropertyFromObject({
+        object: '#mainRelease',
+        property: input.value('commentary'),
+      }),
+
+      exposeDependency({
+        dependency: '#mainRelease.commentary',
+      }),
+    ],
+
+    groups: [
+      withPropertyFromAlbum({
+        property: input.value('groups'),
+      }),
+
+      exposeDependency({
+        dependency: '#album.groups',
+      }),
+    ],
+
     referencedByTracks: reverseReferenceList({
       reverse: soupyReverse.input('tracksWhichReference'),
     }),
@@ -456,14 +513,13 @@ export class Track extends Thing {
 
   static [Thing.yamlDocumentSpec] = {
     fields: {
+      // Identifying metadata
+
       'Track': {property: 'name'},
       'Directory': {property: 'directory'},
       'Suffix Directory': {property: 'suffixDirectoryFromAlbum'},
-
-      'Additional Names': {
-        property: 'additionalNames',
-        transform: parseAdditionalNames,
-      },
+      'Always Reference By Directory': {property: 'alwaysReferenceByDirectory'},
+      'Main Release': {property: 'mainReleaseTrack'},
 
       'Bandcamp Track ID': {
         property: 'bandcampTrackIdentifier',
@@ -475,31 +531,32 @@ export class Track extends Thing {
         transform: String,
       },
 
-      'Duration': {
-        property: 'duration',
-        transform: parseDuration,
+      'Additional Names': {
+        property: 'additionalNames',
+        transform: parseAdditionalNames,
       },
 
-      'Color': {property: 'color'},
-      'URLs': {property: 'urls'},
-
       'Date First Released': {
         property: 'dateFirstReleased',
         transform: parseDate,
       },
 
-      'Cover Art Date': {
-        property: 'coverArtDate',
-        transform: parseDate,
-      },
+      // Credits and contributors
 
-      'Cover Art File Extension': {property: 'coverArtFileExtension'},
+      'Artists': {
+        property: 'artistContribs',
+        transform: parseContributors,
+      },
 
-      'Cover Art Dimensions': {
-        property: 'coverArtDimensions',
-        transform: parseDimensions,
+      'Contributors': {
+        property: 'contributorContribs',
+        transform: parseContributors,
       },
 
+      // General configuration
+
+      'Count In Artist Totals': {property: 'countInArtistTotals'},
+
       'Has Cover Art': {
         property: 'disableUniqueCoverArt',
         transform: value =>
@@ -508,28 +565,65 @@ export class Track extends Thing {
             : value),
       },
 
-      'Always Reference By Directory': {property: 'alwaysReferenceByDirectory'},
+      // General metadata
 
-      'Lyrics': {
-        property: 'lyrics',
-        transform: parseLyrics,
+      'Duration': {
+        property: 'duration',
+        transform: parseDuration,
       },
 
-      'Commentary': {
-        property: 'commentary',
-        transform: parseCommentary,
+      'Color': {property: 'color'},
+
+      'URLs': {property: 'urls'},
+
+      // Artworks
+
+      'Track Artwork': {
+        property: 'trackArtworks',
+        transform:
+          parseArtwork({
+            thingProperty: 'trackArtworks',
+            dimensionsFromThingProperty: 'coverArtDimensions',
+            fileExtensionFromThingProperty: 'coverArtFileExtension',
+            dateFromThingProperty: 'coverArtDate',
+            artTagsFromThingProperty: 'artTags',
+            referencedArtworksFromThingProperty: 'referencedArtworks',
+            artistContribsFromThingProperty: 'coverArtistContribs',
+            artistContribsArtistProperty: 'trackCoverArtistContributions',
+          }),
       },
 
-      'Crediting Sources': {
-        property: 'creditingSources',
-        transform: parseCreditingSources,
+      'Cover Artists': {
+        property: 'coverArtistContribs',
+        transform: parseContributors,
       },
 
-      'Referencing Sources': {
-        property: 'referencingSources',
-        transform: parseReferencingSources,
+      'Cover Art Date': {
+        property: 'coverArtDate',
+        transform: parseDate,
+      },
+
+      'Cover Art File Extension': {property: 'coverArtFileExtension'},
+
+      'Cover Art Dimensions': {
+        property: 'coverArtDimensions',
+        transform: parseDimensions,
+      },
+
+      'Art Tags': {property: 'artTags'},
+
+      'Referenced Artworks': {
+        property: 'referencedArtworks',
+        transform: parseAnnotatedReferences,
       },
 
+      // Referenced tracks
+
+      'Referenced Tracks': {property: 'referencedTracks'},
+      'Sampled Tracks': {property: 'sampledTracks'},
+
+      // Additional files
+
       'Additional Files': {
         property: 'additionalFiles',
         transform: parseAdditionalFiles,
@@ -545,54 +639,41 @@ export class Track extends Thing {
         transform: parseAdditionalFiles,
       },
 
-      'Main Release': {property: 'mainReleaseTrack'},
-      'Referenced Tracks': {property: 'referencedTracks'},
-      'Sampled Tracks': {property: 'sampledTracks'},
-
-      'Referenced Artworks': {
-        property: 'referencedArtworks',
-        transform: parseAnnotatedReferences,
-      },
+      // Content entries
 
-      'Franchises': {ignore: true},
-      'Inherit Franchises': {ignore: true},
-
-      'Artists': {
-        property: 'artistContribs',
-        transform: parseContributors,
+      'Lyrics': {
+        property: 'lyrics',
+        transform: parseLyrics,
       },
 
-      'Contributors': {
-        property: 'contributorContribs',
-        transform: parseContributors,
+      'Commentary': {
+        property: 'commentary',
+        transform: parseCommentary,
       },
 
-      'Cover Artists': {
-        property: 'coverArtistContribs',
-        transform: parseContributors,
+      'Crediting Sources': {
+        property: 'creditingSources',
+        transform: parseCreditingSources,
       },
 
-      'Track Artwork': {
-        property: 'trackArtworks',
-        transform:
-          parseArtwork({
-            thingProperty: 'trackArtworks',
-            dimensionsFromThingProperty: 'coverArtDimensions',
-            fileExtensionFromThingProperty: 'coverArtFileExtension',
-            dateFromThingProperty: 'coverArtDate',
-            artTagsFromThingProperty: 'artTags',
-            referencedArtworksFromThingProperty: 'referencedArtworks',
-            artistContribsFromThingProperty: 'coverArtistContribs',
-            artistContribsArtistProperty: 'trackCoverArtistContributions',
-          }),
+      'Referencing Sources': {
+        property: 'referencingSources',
+        transform: parseReferencingSources,
       },
 
-      'Art Tags': {property: 'artTags'},
+      // Shenanigans
 
+      'Franchises': {ignore: true},
+      'Inherit Franchises': {ignore: true},
       'Review Points': {ignore: true},
     },
 
     invalidFieldCombinations: [
+      {message: `Secondary releases never count in artist totals`, fields: [
+        'Main Release',
+        'Count In Artist Totals',
+      ]},
+
       {message: `Secondary releases inherit references from the main one`, fields: [
         'Main Release',
         'Referenced Tracks',
@@ -779,6 +860,30 @@ export class Track extends Thing {
     ];
   }
 
+  countOwnContributionInContributionTotals(_contrib) {
+    if (!this.countInArtistTotals) {
+      return false;
+    }
+
+    if (this.isSecondaryRelease) {
+      return false;
+    }
+
+    return true;
+  }
+
+  countOwnContributionInDurationTotals(_contrib) {
+    if (!this.countInArtistTotals) {
+      return false;
+    }
+
+    if (this.isSecondaryRelease) {
+      return false;
+    }
+
+    return true;
+  }
+
   [inspect.custom](depth) {
     const parts = [];
 
diff --git a/src/data/things/wiki-info.js b/src/data/things/wiki-info.js
index f97f9027..b6057735 100644
--- a/src/data/things/wiki-info.js
+++ b/src/data/things/wiki-info.js
@@ -13,7 +13,7 @@ import {
   isURL,
 } from '#validators';
 
-import {exitWithoutDependency} from '#composite/control-flow';
+import {exitWithoutDependency, exposeConstant} from '#composite/control-flow';
 
 import {
   contentString,
@@ -119,6 +119,14 @@ export class WikiInfo extends Thing {
         default: false,
       },
     },
+
+    // Expose only
+
+    isWikiInfo: [
+      exposeConstant({
+        value: input.value(true),
+      }),
+    ],
   });
 
   static [Thing.yamlDocumentSpec] = {
diff --git a/src/data/yaml.js b/src/data/yaml.js
index 9a0295b8..71887fc1 100644
--- a/src/data/yaml.js
+++ b/src/data/yaml.js
@@ -87,7 +87,7 @@ function makeProcessDocument(thingConstructor, {
   //   ]
   //
   // ...means A can't coexist with B or C, B can't coexist with A or C, and
-  // C can't coexist iwth A, B, or D - but it's okay for D to coexist with
+  // C can't coexist with A, B, or D - but it's okay for D to coexist with
   // A or B.
   //
   invalidFieldCombinations = [],
@@ -182,9 +182,22 @@ function makeProcessDocument(thingConstructor, {
 
     const fieldCombinationErrors = [];
 
-    for (const {message, fields} of invalidFieldCombinations) {
+    for (const {message, fields: fieldsSpec} of invalidFieldCombinations) {
       const fieldsPresent =
-        presentFields.filter(field => fields.includes(field));
+        fieldsSpec.flatMap(fieldSpec => {
+          if (Array.isArray(fieldSpec)) {
+            const [field, match] = fieldSpec;
+            if (!presentFields.includes(field)) return [];
+            if (typeof match === 'function') {
+              return match(document[field]) ? [field] : [];
+            } else {
+              return document[field] === match ? [field] : [];
+            }
+          }
+
+          const field = fieldSpec;
+          return presentFields.includes(field) ? [field] : [];
+        });
 
       if (fieldsPresent.length >= 2) {
         const filteredDocument =
@@ -194,7 +207,10 @@ function makeProcessDocument(thingConstructor, {
             {preserveOriginalOrder: true});
 
         fieldCombinationErrors.push(
-          new FieldCombinationError(filteredDocument, message));
+          new FieldCombinationError(
+            filteredDocument,
+            fieldsSpec,
+            message));
 
         for (const field of Object.keys(filteredDocument)) {
           skippedFields.add(field);
@@ -416,19 +432,36 @@ export class FieldCombinationAggregateError extends AggregateError {
 }
 
 export class FieldCombinationError extends Error {
-  constructor(fields, message) {
-    const fieldNames = Object.keys(fields);
+  constructor(filteredDocument, fieldsSpec, message) {
+    const fieldNames = Object.keys(filteredDocument);
 
     const fieldNamesText =
       fieldNames
-        .map(field => colors.red(field))
+        .map(field => {
+          if (fieldsSpec.includes(field)) {
+            return colors.red(field);
+          }
+
+          const match =
+            fieldsSpec
+              .find(fieldSpec =>
+                Array.isArray(fieldSpec) &&
+                fieldSpec[0] === field)
+              .at(1);
+
+          if (typeof match === 'function') {
+            return colors.red(`${field}: ${filteredDocument[field]}`);
+          } else {
+            return colors.red(`${field}: ${match}`);
+          }
+        })
         .join(', ');
 
     const mainMessage = `Don't combine ${fieldNamesText}`;
 
     const causeMessage =
       (typeof message === 'function'
-        ? message(fields)
+        ? message(filteredFields)
      : typeof message === 'string'
         ? message
         : null);
@@ -440,7 +473,7 @@ export class FieldCombinationError extends Error {
           : null),
     });
 
-    this.fields = fields;
+    this.fields = fieldNames;
   }
 }
 
@@ -976,6 +1009,12 @@ export const documentModes = {
   // array of processed documents (wiki objects).
   allInOne: Symbol('Document mode: allInOne'),
 
+  // allTogether: One or more documens, spread across any number of files.
+  // Expects files array (or function) and processDocument function.
+  // Calls save with an array of processed documents (wiki objects) - this is
+  // a flat array, *not* an array of the documents processed from *each* file.
+  allTogether: Symbol('Document mode: allTogether'),
+
   // oneDocumentTotal: Just a single document, represented in one file.
   // Expects file string (or function) and processDocument function. Calls
   // save with the single processed wiki document (data object).
@@ -1086,6 +1125,7 @@ export async function getFilesFromDataStep(dataStep, {dataPath}) {
       }
     }
 
+    case documentModes.allTogether:
     case documentModes.headerAndEntries:
     case documentModes.onePerFile: {
       if (!dataStep.files) {
@@ -1241,7 +1281,8 @@ export function processThingsFromDataStep(documents, dataStep) {
   const {documentMode} = dataStep;
 
   switch (documentMode) {
-    case documentModes.allInOne: {
+    case documentModes.allInOne:
+    case documentModes.allTogether: {
       const result = [];
       const aggregate = openAggregate({message: `Errors processing documents`});
 
@@ -1516,6 +1557,10 @@ export function saveThingsFromDataStep(thingLists, dataStep) {
       return dataStep.save(thing);
     }
 
+    case documentModes.allTogether: {
+      return dataStep.save(thingLists.flat());
+    }
+
     case documentModes.headerAndEntries:
     case documentModes.onePerFile: {
       return dataStep.save(thingLists);