The CCNC document that gives the guidlines for all mutual-aid talkgroup and frequency usage is specified in:
http://www.ccncinc.org/userdocs/CCNC Master SOPs rev1.pdf
6.1 REQUIRED CHANNELS AND TALKGROUPS
All voice subscriber units excluding Public Safety Communications Dispatch Center base stations, granted transmission access to DTR are required to include the following channels and talkgroups in their subscriber templates:
1. The National Interoperability Channels (ICALL and ITAC1-4
2. The Statewide Interoperability Channel (S-TAC 5).
3. The Regional Mutual Aid Channels for the region they operate in ie. MAC 1 MET – MAC 4 MET, MAC 5 NE – MAC 8 NE, MAC9 SE _ MAC 12 SE, MAC 13 SW – MAC 16 SW, or MAC 17 NW – MAC 20 NW.
4. The Statewide Mutual Aid Channel CO MAC 21.
5. Also, the Mutual Aid Calling Channels (The first MAC for the region) for the other Regions are recommended for all subscribers.
Public Safety Communications Dispatch Centers refer to section 5.3.2 for base station recommendations.