linkage  _
   boldface,
   buildcrossref,
   compare,
   ds$mem,
   dumpbuffer,
   enterkw,
   exchan,
   getsym,
   gname,
   gopen,
   gremov,
   gtext,
   incom,
   initcrossref,
   lexcom,
   makfil,
   merge,
   ngetch,
   obufcom,
   optcom,
   outch,
   outputkeyword,
   outstr,
   printcrossref,
   ptext,
   putback,
   putbackstr,
   quick,
   reheap,
   skipblanksandcomments,
   sort,
   synerr,
   underline