 data structure. 
 
                  `srfids' optionally may contain a set of surface ID 
                  codes on input; on output, the ID codes already 
                  present in `srfids' will be combined with surface ID 
                  code set found for the body designated by 
                  `bodyid' in the file DSK. 
 
                  If `srfids' contains no data on input, its size and 
                  cardinality still must be initialized. 
 </PRE>
<h4><a name="Detailed_Output">Detaile