(registered 2026-11-09, last updated 2026-11-09)

Scheme name:
xudanu

Status:
Provisional

Applications/protocols that use this scheme name:
The Xudanu hypertext document store (open source, Apache-2.0)
emits and parses these URIs in its wire protocol and its Model
Context Protocol (MCP) agent surface, to cite content with
span-stable, revision-pinnable addresses. Examples:

xudanu://work/42 current edition of work 42
xudanu://work/42?rev=3 revision 3, pinned and immutable
xudanu://work/42#span=10,150 characters 10-150 of the work

Contact:
David Jones <david&dgjones.info>

Change controller:
David Jones <david&dgjones.info>

References:
Xudanu URI Scheme v1.0 (the specification this registration
points at):
https://dgjones.info/xudanu/uri-scheme.html

Xudanu MCP Guide, section 5, "Addressing":
https://dgjones.info/xudanu/mcp-guide.html

The specification defines the syntax (ABNF grammar), component
semantics, canonical form and tolerated input, comparison rules,
dereferencing with BLAKE3 content-hash verification, and security
considerations. The authority literal "work" is reserved permanently,
which keeps v1 addresses unambiguous as future authority forms are
added in later revisions of the specification at the same URL.