http://www.rfc-editor.org/rfc/rfc2370.txt
RFC 2370: The OSPF Opaque LSA Option, R. Coltun1998-07-01T23:00:00-00:00This memo defines enhancements to the OSPF protocol to support a new class of link-state advertisements (LSA) called Opaque LSAs. [STANDARDS-TRACK]