Incspy.cfg is what you would use when you are announcing an incoming spy's disguise.

The default settings are (you can change them if you want in unfriendly.cfg):

F1 Incoming SPY is disguised as a SCOUT"
F2 Incoming SPY is disguised as a SNIPER"
F3 Incoming SPY is disguised as a SOLDIER"
F4 Incoming SPY is disguised as a DEMOMAN"
F5 Incoming SPY is disguised as a MEDIC"
F6 Incoming SPY is disguised as a HWGUY"
F7 Incoming SPY is disguised as a PYRO"
F8 Incoming SPY is disguised as a friendly SPY"
F9 Incoming SPY is disguised as an ENGINEER"
F10 Incoming SPY is UNDISGUISED"
F11 Incoming SPY has an UNKNOWN DISGUISE"