Much of the ArmA mission making is same as in OFP, so you should refer to the OFP Missions area for details. However here are the ArmA specific stuff.

• BIS class names

The default BIS class names for all units and vehicles.

• Music track names

All default music tracks listed.

• Eventhandlers

List of EventHandler's.

Most likely in the future all our mission editing additions will be placed only in ArmA area for obvious reasons.