Tag Taxonomy — Controlled Vocabulary for Wiki Tags

You are enforcing consistent tagging across the wiki by normalizing tags to a controlled vocabulary.

Before You Start

1. Resolve the vault path (precedence, highest first): the OBSIDIAN_VAULT_PATH environment variable if set, else a .env in the current working directory (vault-scoped), else ~/.obsidian-wiki/config (global default).
2. Read $OBSIDIAN_VAULT_PATH/_meta/taxonomy.md — this is the canonical tag list
3. Read index.md to understand the wiki's scope

The Taxonomy File

The canonical tag vocabulary lives at $OBSIDIAN_VAULT_PATH/_meta/taxonomy.md. It defines:

• Canonical tags — the tags that should be used
• Aliases — common alternatives that should be mapped to the canonical form
• Rules — max 5 tags per page, lowercase/hyphenated, prefer broad over narrow
• Migration guide — specific renames for known inconsistencies

Always read this file before tagging. It's the source of truth.

Reserved System Tags

visibility/ is a reserved tag group with special rules. These tags are not domain or type tags and are managed separately from the taxonomy vocabulary:

Rules for visibility/ tags:

• They do not count toward the 5-tag limit
• Only one visibility/ tag per page
• Omit entirely when content is clearly public — no tag needed
• Never add visibility/internal just because content is technical; use it only for genuinely team-restricted knowledge
• When running a tag audit, report visibility/ tag usage separately — do not flag them as unknown or non-canonical

When normalizing tags, leave visibility/ tags untouched — they are not subject to alias mapping.

Mode 1: Tag Audit

When the user wants to see the current state of tags:

Step 1: Scan all pages

Glob: $VAULT_PATH/**/*.md (excluding _archives/, .obsidian/, _meta/)
Extract: tags field from YAML frontmatter

Step 2: Build a tag frequency table

For each tag found, count how many pages use it. Flag:

• Unknown tags — not in the taxonomy's canonical list
• Alias tags — using an alias instead of the canonical form (e.g., nextjs instead of react)
• Over-tagged pages — pages with more than 5 tags
• Untagged pages — pages with no tags or empty tags field

Step 3: Report

## Tag Audit Report

### Summary

- Total unique tags: 47
- Canonical tags used: 32
- Non-canonical tags found: 15
- Pages over tag limit (5): 3
- Untagged pages: 2

### Non-Canonical Tags Found

| Current Tag | → Canonical | Pages Affected |
| ----------- | ----------- | -------------- |
| `nextjs`    | `react`     | 4              |
| `next-js`   | `react`     | 2              |
| `robotics`  | `ml`        | 1              |
| `windows98` | `retro`     | 3              |

### Unknown Tags (not in taxonomy)

| Tag          | Pages | Recommendation                   |
| ------------ | ----- | -------------------------------- |
| `flutter`    | 1     | Add to taxonomy under Frameworks |
| `kubernetes` | 2     | Add to taxonomy under DevOps     |

### Over-Tagged Pages

| Page                   | Tag Count | Tags                 |
| ---------------------- | --------- | -------------------- |
| `entities/jane-doe.md` | 8         | ai, ml, founder, ... |

Mode 2: Tag Normalization

When the user wants to fix the tags:

Step 1: Run audit (above)

Step 2: Apply fixes

For each page with non-canonical tags:

1. Read the page
2. Replace alias tags with their canonical form from the taxonomy
3. If page has > 5 tags, suggest which to drop (keep the most specific/relevant ones)
4. Write the updated frontmatter

Example:

# Before
tags: [nextjs, ai, ml-engineer, windows98, creative-coding, game, 8-bit, portfolio]

# After
tags: [react, ai, ml, retro, generative-art]

Step 3: Handle unknowns

For tags that aren't in the taxonomy and aren't aliases:

• If the tag is used on 2+ pages, suggest adding it to the taxonomy
• If the tag is used on 1 page, suggest replacing it with the closest canonical tag
• Ask the user before making changes to unknown tags

Step 4: Update taxonomy

If new canonical tags were agreed upon, append them to _meta/taxonomy.md in the correct section.

Mode 3: Tagging a New Page

When you're creating a wiki page and need to choose tags:

1. Read _meta/taxonomy.md
2. Select up to 5 tags that best describe the page:
   • 1-2 domain tags (what subject area)
   • 1 type tag (what kind of thing)
   • 0-1 project tags (if project-specific)
   • 0-1 additional descriptive tags
3. Use only canonical tags — never aliases
4. If no existing tag fits, check if it's worth adding to the taxonomy

Mode 4: Adding a New Tag

When the user wants to add a tag to the vocabulary:

1. Check if an existing tag already covers the concept (suggest it if so)
2. If genuinely new, determine which section it belongs in (Domain, Type, Project)
3. Add it to _meta/taxonomy.md with:
   • The canonical tag name
   • What it's used for
   • Any aliases to redirect

After Any Tag Operation

Append to log.md:

- [TIMESTAMP] TAG_AUDIT tags_normalized=N unknown_tags=M pages_modified=P

Or for normalization:

- [TIMESTAMP] TAG_NORMALIZE tags_renamed=N pages_modified=M new_tags_added=P

hot.md — Read $OBSIDIAN_VAULT_PATH/hot.md (create from the template in wiki-ingest if missing). Update Recent Activity with a one-line summary — e.g. "Tag audit: normalized 14 tags across 28 pages; 2 new canonical tags added." Keep the last 3 operations. Update updated timestamp.