As per ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change,

remove the so-called advertising clause from these files' license,
making it compatible with the Debian Free Software Guidelines.  As
these files were obtained from FreeBSD, this change was discussed
with and approved by the FreeBSD core team.

git-svn-id: http://www.varnish-cache.org/svn/trunk@1208 d4fa192b-c00b-0410-8231-f00ffab90ce4

include/compat/vis.h

@@ -10,11 +10,7 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *	This product includes software developed by the University of
- *	California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
+ * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *

lib/libcompat/vis.c

@@ -10,11 +10,7 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *	This product includes software developed by the University of
- *	California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
+ * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *