Associate the symbolic name name with the branch or revision rev. Delete the symbolic name if both : and rev are omitted; otherwise, print an error message if name is already associated with another number. If rev is symbolic, it is expanded before association. A rev consisting of a branch number followed by a . stands for the current latest revision in the branch. A : with an empty rev stands for the current latest revision on the default branch, normally the trunk. For example, rcs -nname: RCS/* associates name with the current latest revision of all the named RCS files; this contrasts with rcs -nname:$ RCS/* which associates name with the revision numbers extracted from keyword strings in the corresponding working files.