[aprssig] Tactical call signs

[John Habbinga]

This might be legal as long as you don't setup your path for digipeating and 
you don't use APRS messaging through an I-Gate to RF.

> Yep.  Legal.  Not only that, you can even identify in Morse code
> every 10 minutes and keep everything tactical.  That satisfies the
> FCC identification rules.  Of course that last would probably be
> considered bad practice, but it's certainly allowed.