Question regarding GPL

[Alfred M. Szmidt]

   > Only if one considers a work that lacks a copyright header
   > something that is in the public domain, which I belive is not the
   > case.

   Well, certainly work that is PD would not have a copyright header,
   because it wouldn't be in the public domain if it was copyrighted.
   However, a copyrighted work doesn't have to have a copyright header.

I thought that PD works must have a header that notes that it is in
the public domain.  Which is more or less a copyright header, since PD
still falls under the laws of copyright law.  But oh well..

Cheers.