Summary

  • RFC 9896 permits SVG drawings in definitive RFCs while requiring that the concept also be represented in text and that the drawing remain consistent with that text.
  • RPC acceptance proves bounded publication admissibility. It does not prove identical pixels across formats, accessible rendering on every path, reader comprehension or a correct downstream decision.

One protocol relationship enters the definitive RFCXML as text beside a diagram. HTML renders a wide colour version. PDF fits the same relationship to a page. A small screen scales it. An assistive path exposes another representation. The outputs need not share every pixel; they do need to preserve the same meaning.

RFC 9896, published in January 2026 in the Editorial Stream, replaces the fixed-profile approach of RFC 7996. It retains policy but removes the requirement to bind the Series to one SVG profile or implementation code. The RFC Production Center chooses tooling and may change it as the authoring community and display environment change.

That flexibility is not a transfer of semantic authority to the renderer. The policy says a drawing may explain a concept but should not be its only representation. Authors should make a good-faith effort to represent protocols, formats and architectures fully in text. At minimum, the image must agree with the text. A green publication check therefore answers a bounded question: was this artwork admitted under the applicable production rules? It does not answer whether the picture silently adds a branch, removes a condition or makes an optional path look mandatory.

The format model makes the distinction operational. RFC 9720 defines RFCXML as the definitive format and the published XML as the definitive version. HTML, plain text and PDF are publication versions rendered from that source. RFC 7991 supplies the source vocabulary in which artwork is embedded. The definitive file is self-contained and carries the information intended for the RFC; a particular screen image is one projection of that record.

RFC 9896 constrains that projection. SVG cannot contain executable script or pointers to external resources. It cannot animate or offer interactive features. Limited reactions such as scaling or dark/light adaptation are permitted only within an intent that meaning not change. Those rules reduce hidden dependencies and mutable behavior. They do not prove that the visual hierarchy is correct, that colour carries no exclusive meaning, or that a screen reader exposes an equivalent explanation.

Accessibility is therefore a separate evidence surface. The RPC may reject features that fail on common devices, small screens or low-resolution displays, and it should seek accessibility for readers with visual disabilities. The policy points toward the W3C accessibility standards, while the broader SVG 2 specification describes a language whose capabilities exceed the RFC subset. W3C validity, RPC admissibility and observed accessibility are three different records.

Authors may supply multiple versions of an image, and each publication format may select the one best suited to it. That is useful, but it creates a reconciliation duty. The evidence package should bind a text claim map to the definitive source hash, each alternate artwork hash, the policy and tool versions, rendered outputs, zoom and contrast tests, accessible names or descriptions, and an archive timestamp. When the source or tool changes, semantic comparison matters more than pixel comparison.

The policy makes implementation change explicit. SVG vocabulary and tooling may evolve; backward compatibility is encouraged but not guaranteed. The RPC can impose technical and editorial limits, but must document acceptable use, communicate changes widely, seek community input and explain its reasoning. RFC 9280 supplies the wider governance separation, while the RFC Editor record establishes the publication identity. Neither record proves how a named renderer behaved today.

Heng Lu's minimum-initial-specification principle clarifies the architecture: preserve the narrow shared semantic obligation, then let implementation decisions remain local and accountable. Running-code primacy requires checking the actual render and accessible path. The reality-layers distinction prevents an accepted symbol from being promoted into proof of reader understanding.

The durable rule is simple. A diagram can enter the definitive record. It cannot replace the proposition against which every rendering must still be tested.

Sources