multiple principals in one cache?

[Abe Singer]

According to kinit(1), when doing a kinit "Any existing tickets for _principal_
are overwritten."  However, we've found that *all* tickets are destroyed.
So if one does a kinit for user at REALM-1, then does a kinit for user at REALM-2, the
tickets for user at REALM-1 get deleted from the cache.

We'd *like* to be able kinit multiple principals for use with services
in different realms (e.g. working realm and test realm).  Is the behavior
we're seeing intentional (an the documentation is buggy) or a bug?