title : Edges crease marks on .obj exports

Hello, is there any infos about how edge creases are marked on .obj exported models.

Is there an angle threshold at which edges are marked ? is there a workaround to export, trim, or select only theses hard edges in MoI ?

I just try to understand how to handle the exported polys. Maybe I'm missing something about NGons.

thx

Edit : forgot to title the thread. cant change it.