OSIG has several regions according to publicly available info on the web. The Bureau of Fraud Prevention group is divided into Western, Central, Southeastern, and Northeastern regions. 13472 seems to have been serving as the main talkgroup for SE activity. 13466 has been IDd over the air as "WRO1". Somewhere, I read that a listener had heard 13468 referred to as "WRO3". I have seen affiliations with every talkgroup between 13466 and 13477 via channel flipping when the new radios went on the air. Purely based on these tidbits, I made the leap that each of the four regions has three channels assigned. That could be totally wrong. Someone else added this speculation to the wiki based on an earlier post I made.