MASTER_AUTO_POSITION always needed for GTID replication? (no replies)

Trying to understand when MASTER_AUTO_POSITION is required to be set to 1. Is this only when you are enabling GTID based replication hot when you already had the log position based replication before? Or is this always needed to be 1 regardless if you are using GTID based replication? i.e. if I'm just enabling new replication from scratch?

Thanks.