This file may contain proprietary rules that were created, tested and tested and certified by Sourcefire, Inc. (the “VRT Certified Rules”) as well as other rules that are distributed under the GNU General Public License (GPL Rules) This file contains a version of Snort’s version 2.3.3 (C) Copyright 2001-2004, Martin Roesch, Brian Caswell, et al. All rights reserved. Snort rules read 2699.99: Rule chains linked into 193 Chainers. Oinkmaster is now running in IDS mode.”]
Source: https://taosecurity.blogspot.com/2005/06/trying-snort-vrt-rules-and-oinkmaster.html