All the files must contain the CVS Id header.

If you create a new file, the first line must be:

<!-- $Id: -->

The first time it is committed to CVS (and every time it is committed to CVS) the line is updated automatically to include information about the file. For example:

<!-- $Id: docs-rh-guidelines-en.xml,v 1.2 2004/08/31 15:45:29 tfox Exp $ -->