I would do what Cakemom offered!
In the US riders are granted (AA) status by (signing an affidavit with) the usEf, the usDf only writes the freestyle and walk/trot tests, the rest is administered by the usEf. It is not just saying you are an AA, but signing to it as well. Otherwise the rules are those of the usEf (guidelines from the fei). And although your group might say 'under the usef rules', there is no 'teeth' in that because there is no TD, or repercussions from violating the rules. (That is why there are no longer usDf league shows). If it is recognized show, go to the TD if these are AA classes (vs maidin or open or etc).