Reference
Standards & sources.
The standards behind content negotiation.
Internet standards
- RFC 9110 §12.5.1
- Proactive Content Negotiation. Defines how a server uses
Accept(and related) to select a representation. - RFC 9110 §12.5.5
- The
Varyheader field. Required for correct downstream caching of negotiated responses. - RFC 9110 §15.5.7
406 Not Acceptable. The right response when the client's Accept header can't be satisfied.- RFC 7763
- The
text/markdownmedia type registration. - RFC 7764
- Companion to RFC 7763 — guidance on Markdown variants and the
variantparameter. - RFC 8288
- Web Linking. Defines the
LinkHTTP header and therelattribute registry — useful for advertising an alternate.mdrepresentation viarel="alternate"; type="text/markdown". - IANA media type registry
- The authoritative record for
text/markdown.
Developer docs
- MDN — Content negotiation
- Approachable overview with examples. The canonical "what is it" page.
- MDN —
Accept - Syntax, q-values, and directives for the request header clients use to advertise preferred media types.
- MDN —
Vary - The response header that tells caches which request headers (like
Accept) affect the selected representation. - Cloudflare — Markdown for Agents
- Cloudflare's managed feature that serves Markdown at the edge with no origin changes. The zero-config baseline.