Maybe read RFC4271 instead if you're looking to learn about the protocol rather than just about this implementation, just be aware there are many extension RFCs

Maybe read RFC4271 instead if you're looking to learn about the protocol rather than just about this implementation, just be aware there are many extension RFCs (see the list at the top of the link). https://datatracker.ietf.org/doc/html/rfc4271 https://datatracker.ietf.org/doc/html/rfc4271