For Players who aren't keen to examine their FRS or GMRS radio transceivers, this is a brief note about the squelch codes ("subchannels").
We generally use FRS and GMRS frequencies for communication, and these are conveniently grouped into channels 1 to 14 (FRS) and 15 to 22 (GMRS). To these channels we can apply squelch codes to further split up the radio-space. Squelch codes are not extra channels, they are filters you can use to ignore other squads.
You can only transmit and receive on the squelch code you are set. For example, if you set your radio to 1-1, you can only transmit to people on 1-1 but people on both 1-0 and 1-1 can hear you.
Squelch code 0 is special: it will allow you to hear all of the traffic on the set channel regardless of squelch code. But it also limits your transmissions to people who are using squelch code 0.
The biggest disadvantage of using squelch codes is that if anyone is transmitting on the channel, all squelch codes have to wait until the transmission is done before they can use the channel. Even if they don't hear anyone talking!
The best alternative is to set squads on their own channels and command on another channel. Squad leaders best to have 2 radios-- one on each channel. And main leaders best to have 2 radios-- one on the admin channel and one on the team command channel.