Guidelines for converting W3C specs to Bikeshed format. Covers anchor ID preservation, dfn handling, and common pitfalls. Read this before any Bikeshed conversion or migration work.
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2Install
npx skillscat add w3c/web-performance/bikeshed-conversion Install via the SkillsCat registry.
Bikeshed Conversion
Preserving Anchor IDs
When converting a spec to Bikeshed, anchor IDs used by other specifications must be preserved. Bikeshed auto-generates IDs for <dfn> elements based on their text content, but these auto-generated IDs often differ from the IDs that were in the original spec. Other specs link to these IDs, so changing them silently breaks cross-spec references.
The Problem
Bikeshed generates IDs like dfn-wall-clock from <dfn>wall clock</dfn>, but the original spec may have used a different ID or no explicit ID (relying on the HTML spec's own ID generation). When other W3C specs reference anchors like #dfn-wall-clock, #dom-performance, or #dfn-coarsen-time, those links break if the IDs change.
The Fix
Always add explicit id attributes to <dfn> elements to preserve the anchors other specs depend on:
<!-- BAD: Bikeshed auto-generates an ID that may differ from the original -->
<dfn data-export>wall clock</dfn>
<!-- GOOD: Explicit ID preserves the anchor -->
<dfn data-export id=dfn-wall-clock>wall clock</dfn>Common ID Patterns to Preserve
Based on w3c/hr-time#173, these are typical ID patterns that get lost:
| Type | Pattern | Example |
|---|---|---|
| Concept definitions | dfn-{name} |
id=dfn-wall-clock, id=dfn-monotonic-clock, id=dfn-duration |
| Algorithm definitions | dfn-{algorithm-name} |
id=dfn-coarsen-time, id=dfn-duration-from |
| IDL typedefs | dom-{typename} |
id=dom-domhighrestimestamp, id=dom-epochtimestamp |
| IDL interfaces | dom-{interface} |
id=dom-performance |
| IDL blocks | idl-def-{name} |
id=idl-def-domhighrestimestamp |
| Compound concepts | dfn-{hyphenated} |
id=dfn-current-high-resolution-time, id=dfn-relative-high-resolution-coarse-time |
Checklist
When converting a spec to Bikeshed:
- Inventory all
<dfn>elements in the original spec and note their IDs - Check for cross-spec references — search other W3C specs that link to this spec's anchors (use xref or grep the spec's URL in other repos)
- Add explicit
idattributes to every<dfn>that had an ID in the original, matching the original ID exactly - Verify after conversion — build the Bikeshed output and confirm all anchors from the original spec still resolve
- Check
data-dfn-forscoping — Bikeshed usesdata-dfn-forto scope definitions; make sure scoped dfns also retain their original IDs (e.g.,id="wall-clock-unsafe-current-time"for<dfn data-dfn-for="wall clock">unsafe current time</dfn>)