The package defines two commands:
– \eachlabelcase, which distinguishes whether a set of labels is defined, and for each label either queues action accordingly, or appends the action to a macro; and
– \lotlabelcase, which takes a comma-separated list of label names, and distinguishes the resulting action on whether all were defined, whether none were defined, whether not all were defined, or whether the lest is empty (again, the action resulting from \lotlabelcase may be written to a macro).

The author is Ulrich Diez. The package is Copyright © 2006 Ulrich Diez.