POSITION

 POSITION = pos

 pos   Is a scalar default character variable that is assigned
       one of the following values:

 'REWIND'    If  the file is connected with its position 
             at its initial point

 'APPEND'    If the file is connected with its position 
             at its terminal point (or before its end-of-file 
             record, if any)

 'ASIS'      If the file is connected without changing 
             its position

 'UNDEFINED' If the file is not connected, or is connected 
             for direct access data transfer and a REWIND 
             statement has not been performed on the unit.