Arming, servo_function, TKOFF

Hey all,

i search for a better understanding/description about the servoX_function parameter.
I need a more complete description like this:
http://ardupilot.org/plane/docs/channel-output-functions.html

  1. possible, somebody can point me to the code.

  2. I need a parameter, who get high, after the arming (with TKOFF_ACCEL) is recognized. (For releasing reason)

  3. Is there a way to arm the plane in a special manner?
    In example:
    TKOFF_ACC had 15
    TKOFF_VEL has > 5
    TKOFF_ACC had < 5

I promise to learn C++ next time. );

Thanks many times.