Implementers’ Draft: XRDS-Simple 1.0 Draft 1
“XRDS-Simple provides a format and workflow for the discovery of resources metadata, and other linked resources.”
#specification
The Atom Publishing Protocol
The Atom Publishing Protocol (APP) is an application-level protocol for publishing and editing Web resources. The protocol is based on HTTP transfer of Atom-formatted representations. The Atom format is documented in the Atom Syndication Format.
RSS Autodiscovery
From the RSS Advisory Board – official documents on how to implement auto-discovery
The Atom Syndication Format
Official, hyperlinked spec