Suffixes_precedence_list

   The suffixes precedence list is a list of  all  the  file  types  MMS
   recognizes,  arranged in a predetermined order.  MMS uses the list to
   decide which built-in rule to apply based on the order of  the  types
   in the list, the file type of the target currently being updated, and
   the existence of source files in the specified directory.

   You can  alter  the  suffixes  precedence  list by using  one  of the
   .SUFFIXES... directives.