http://www.rfc-editor.org/rfc/rfc1370.txt
RFC 1370: Applicability Statement for OSPF, , L. Chapin1992-10-01T23:00:00-00:00This Applicability Statement places a requirement on vendors claiming conformance to this standard, in order to assure that users will have the option of deploying OSPF when they need a multivendor, interoperable IGP in their environment. [STANDARDS-TRACK]