where does RCS get the user name from?

[Ed]

Howdy!

I am trying to use RCS. When I lock a file it seems to work but shows
that the file is EHartnett. How does it know my name? I never set that
anywhere...

Also, when I try and work with the file again, emacs makes me send an
email to EHartnett because it thinks I am someone else. How do I tell
emacs and RCS what my user name is, so that they both argee as to who
I am?

Thanks!

Ed