With a full ClearCase installation, CLEARCASE_PRIMARY_GROUP
is the usual way to set the main group for a user.
What about a CCRC installation through CLI (Java CM CLI or CCRC CLI)?
The GUI allows to set a primary group, but how would you set it through command lines?
With CCRC, the technote swg21423936 mentions:
The only workaround is to set a default primary group on the server side (the CM CCRC server)