OSPF Updates are not mentioned in RFCs


as you can see here in the updates there are some numbers

Updated by: 5709, 6549, 6845, 6860, 7474, 8042

R1(config)[#router ospf 1


rfc1583 compatible with RFC 1583

rfc1587 compatible with RFC 1587

R1#show ip ospf | include RFC

Supports NSSA (compatible with RFC 3101)

why these numbers 3101,1583,1587 are not mentioned in the RFC updates ?