Routing protocols start out with some baseline capabilities as described in their original RFCs (and updated by the subsequent RFCs that “obsolete” them). Dev teams implement these capabilities and deliver them to market. At some point, the market ma...

A Cisco Press book provides a good summary of NSF/SSO vs GR vs NSR: https://www.ciscopress.com/articles/article.asp?p=1395746&seqNum=2   OSPF GR extensions: RFC 3623 BGP GR extensions: RFC 4274, RFC 8538  

The CDETS database used by Cisco to store defect details has many more status options than just the four listed (Open, Fixed, Other, Terminated) on the publicly accessible Bug Search Tool Help page. For example, IIRC, “R” for Resolved, “J” for Junked...