It's mentioned in the 1.8t stage 1 tuning thread:
http://nefariousmotorsports.com/forum/index.php?topic=6955.45and is also defined in the xdf mentioned.
I'm attempting to create a simplified version of user pike's H box xdf in order to compare it to the xdf presented in that thread and hopefully learn some about tuning. There's a lot of similarities but the addressees are different and there are some things in the AK xdf that aren't defined in the userpike one. Also user pike's xdf is enormous with a lot of things not pertaining to a stage 1 so I want to get rid of all that for a little.