Some lighting companies reverse + and - on their fixtures, either across the board or on just certain models. It's a common enough problem that some ADJ hardware controllers have a reverse switch to address this problem. This issue can also be addressed by a phase reversing cable.
Other than that, DMX is DMX, it's a standard.
This is NOT to be confused with older European audio gear that uses Pin 3 hot as opposed to American(and now standard) Pin 2 hot. Of course, if you use all your gear phase reversed, does it really make a difference?