Well, I don't know what command term Blender uses, but for use in Poser's new fitting room, what is important is that each garment is a single connected mesh (or group things like belts as constrained, and buttons as rigid decorations).  Many conforming clothing items have collars, cuffs, pockets, and hemlines which are not actually connected to the body of the shirt, for example.  If you try to use it as dynamic cloth, it falls apart.  Similarly, in the fitting room, the pieces pull apart here and there.

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5