layer_00=Default -> the default SolidLayer
layer_01=sketch -> all sketches
layer_02=plane -> all planes
layer_03=Loop -> loops in sketches
layer_04=cossketch -> no longer in use
layer_05=connect -> connection points
layer_06=solid -> Solid body
layer_07=centerline -> e.g. rotational axes
layer_08=thread -> threads
layer_09=component -> assembly components
layer_10=mates -> mates
layer_11=ports -> piping ports