UNSPEC(0;K==>c,((8,b));) returns the real bits of the key in b. It is the primary tool used by a Key Indexed Directory {(kid)}. {UNSPEC returns zero if the key has been deleted (severed)}. If c isn't 0 then c=1 and the key is rather new. Holders of UNSPEC must limit themselves from calling UNSPEC when c=1. Strange overhead is otherwise suffered. For this and other reasons UNSPEC will be of limited distribution.

See (rel-unspec) for another idea that may be implemented in place of UNSPEC.