D2 is the same as Dsus2.

Unfortunately, (or maybe its fortunate, depeding upon how you look at it--) but there are no actual standards for fake chord notation, so there will be those slight discrepancies like this one to be found from time to time.

D2 is the same notes as a Dsus2.

BTW BIAB uses the convention of treating just plain 'sus' as meaning 'sus4'.


--Mac