- union index: placement grouping, mainly for components
- user routed: when explicitly false, the object is placed by the autorouter
- fill object on plane layer is poly hole; no other drawing objects on planes
- mech layers: there are normally 4, the format has 16; they should all be
  boundary; protel users can set if a mech layer is copied to all layers
- altium 13.x won't do multiline text or non-uniform pstk
