How do I make a copy of a tag

[Tony Obermeit]

I have a tag that exists on previous revisions.  I want to make a copy of 
the tag and then change the reference on several files to a newer revision.

Old tag

file1 1.1
file2 1.3
file3 1.8


New tag

file1 1.3
file2 1.3
file3 1.8

I know the command to change the revision reference on a tag but have 
searched the archives and documentation to no avail trying to determine how 
to simply copy a tag so the new tag points to exactly the same revisions as 
the old tag.

thanks

Tony