FMOD_DEFAULT question

Hi, I am trying to understand what FMOD_DEFAULT means:

For example, if I combine modes like this FMOD_DEFAULT | FMOD_CREATESTREAM | FMOD_LOOP_NORMAL for a song, I understand that FMOD will 1) create a stream first in order to play it and 2) loop the song once it reaches the end.

What does FMOD_DEFAULT do in this case?

Thanks,
Simon