[cvsnt] Changing branch tag labels?

[coliva at simon.com]

We have some developers that haven't been following our naming standards
and have been creating confusion with their branch tag names.

I know that is possible to change regular labels by:
     1) Adding the new label where the old label exists:
          cvs rtag -r oldlabel newlabel modulename
     2) Removing all instances of the old label:
          cvs rtag -d oldlabel modulename

Is it possible to do the same with branch tags?  I've been experimenting
with it and haven't found a working solution.