Errors & renderers

Errors (fail closed)

All of the following are hard errors, not warnings:

• a ref whose path does not exist at the resolved rev
• a symbol fragment matching zero or multiple declarations
• a region fragment with no matching marker pair
• duplicate region names in one file; unmatched begin/end
• an alias not declared in docref.toml; an alias declared but absent from docref.lock
• a nested claim
• a malformed reference (unparseable attributes, missing docref=/src=)

Renderers (informative)

Renderers need no docref support: fences are ordinary code blocks and claim comments are invisible. A renderer that opts in may, for example, show a provenance caption on fences ("from handler.go", linking to the source at the locked rev), render a verified badge on claims, or resolve and display an anchor's current contents at build time by invoking the resolver. Such integrations are out of scope for the format and must not change document semantics for other renderers.