These are boolean attributes that correspond to the flags in the object's
gadget.gadgettype field.  if the value passed with the attribute is true,
the corresponding flag in Gadget.GadgetType is set.  If the value passed
with the attribute is FALSE, the corresponding flag in Gadget.GadgetType
is cleared.  See the <intuition/intuition.h> include file or the
"intuition gadgets" chapter of the amiga rom kernel reference manual:
Libraries for more information.