bikeshed-conversion

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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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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 id attributes 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-for scoping — Bikeshed uses data-dfn-for to 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>)