Role::Identifiable::HasIdent is an incredibly simple role. It adds
a required ident attribute that stores a simple string, meant to
identify exceptions.
Role::Identifiable::HasTags adds the ability for your class and its
composed parts (roles, superclasses) as well as instances of it to
contribute to a pool of tags describing each instance.

WWW: http://search.cpan.org/dist/Role-Identifiable/