ILBM has several defined property chunks that act on the main data chunks.
The required property "bmhd" and any optional properties must appear
before any "body" chunk.  (since an ilbm has only one body chunk, any
following properties would be superfluous.)  Any of these properties may
be shared over a list of several ilbms by putting them in a prop ilbm (see
the EA IFF 85 document).

 bmhd 
 cmap 
 grab 
 dest 
 sprt 
 camg