On Sat, 20 Jan 2001, Warner Losh wrote:
> In message <20010120112339.E399@dr-evil.shagadelic.org> Jason R Thorpe writes:
> : If it were a driver originally obtained from FreeBSD, that'd be one
> : thing, but a list of device IDs, seems totally pointless.
> The only diffs between FreeBSD's copy and NetBSD's copy of this file
> right now are the $xxxBSD$ headers.  As things drift, it is nice to
> know the anchor point for that drift so that it can be corrected.

It makes sense that you want that information, but it seems that the
information is already present in CVS commit log messages (of the form
"Synced with changes from XxxBSD version Y.YY").

If the commit log is not sufficient and you also need version numbers in
the file itself, then I'd suggest a comment like this in the file:

/*
 * This file originated in NetBSD, but now both FreeBSD and NetBSD
 * maintain almost identical copies.  To assist with synchronisation
 * between the two systems, we keep both FreeBSD and NetBSD CVS Id tags
 * here.
 *
 * If you are looking at the NetBSD version of this file, then the
 * NetBSD tag is automatically updated, and the FreeBSD tag is manually
 * updated when changes from FreeBSD are merged into NetBSD.  Or vice
 * versa if you are looking at the FreeBSD version of this file.
 *
 * $NetBSD: foo $
 * $FreeBSD: bar $
 */

--apb (Alan Barrett)