This document is about using the reliable flooding mechanism of IS-IS to advertise information for applications unrelated to IS-IS in a way that doesn't use up "T" values in the TLV encoding. So, since it's just syntax, there really aren't any security considerations. It would have been nice if the authors explained what "V" "I" "D" and "S" mean in the context of the flags, as in, what word is "V" the first letter of, what word is "I" the first letter of... Unless I missed it in the spec, the authors just give rules like: D bit (0x02): When the GENINFO TLV is leaked from level-2 to level-1, the D bit MUST be set. Otherwise this bit MUST be clear. GENINFO TLVs with the D bit set MUST NOT be leaked from level-1 to level-2. This is to prevent TLV looping. I bit (0x04): When the I bit is set the 4 octet IPv4 address associated with the application immediately follows the Application ID. Radia