SEO

I remember seeing a comment regarding the topic a few days ago on a
patch. But I can't seem to find it in the archive.

Anyways, I was browsing through the /usr/src and noticed that most c
files begin with something like:

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)cat.c 8.2 (Berkeley) 4/27/95";
#else
static char rcsid[] = "$OpenBSD: cat.c,v 1.17 2005/04/05 01:18:53 jaredy
Exp $";
#endif
#endif /* not lint */


My question is why is this used twice? and not in a single #ifndef?

Thanks,
Paul.