[x3d-public] ParticlePhysics > VolumeEmitter and SurfaceEmitter > puzzling fields

[doug sanden]

http://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/particle_systems.html#SurfaceEmitter
SurfaceEmitter
SFNode surface [X3DGeometryNode]
MFInt32 set_coordIndex
MFInt32 coordIndex

Q1. if I have the geometry in the surface field, what do I need set_coordindex/coordIndex fields for?

VolumeEmitter
MFInt32 set_coordIndex
MFInt32 coordIndex
SFNode coord [X3DCoordinateNode]

Q2. wouldn't it have been easier for content developers if VolumeEmitter had a geometry field (like SurfaceEmitter):
SFNode volume [X3DGeometryNode]
Otherwise if using a indexedfaceset-like interface, to define a cylinder or sphere its a lot of work for the content developer. Or if its intentional -so a simpler sphere could be defined- X3DGeometryNode field would allow content developer to use IFS to define a simpler sphere.
Or is this a mis-print/typo mistake in the specs and there's a hidden/missing SFNode field?

-Doug