about LOD in MD4

I just find out that the MD4 model data in Quake3TA supports LOD rendering. Does anyone know how JC do that? I can hardly find any infomation about programming with MD4.

I though from the presentation Brian Hook gave was that the Original Quake 3 was suppose to support plain old “poping” LOD ==> in english : different resolution of the models are stored in the model file an not attempt is done for smoothing the LOD switch.