Why "unset USERNAME" in .bash_profile?

[Filipe Brandenburger]

Hello,

I would like to know why in FC2 and FC3 there's this command in the
default .bash_profile:

    unset USERNAME

I googled for it, and didn't find any reference to a USERNAME
environment variable, and I didn't find any process that sets it before
the shell is started to unset it in .bash_profile...

Does anyone know what is it? Why is it being unset? Is there a reason to
keep it? Or can I just ignore it and use the .bash_profile I used to
have in other distro's?

Thanks!
Branden