UNIX YACC (CSD Variant):
   yacc -hist tag infile

Switches:
   -h     Create definitions header file
   -i     Create parser description file
   -t tag Prepends tag to tables
   -s     Generates extended tables (MIDL specific)

Default input file extension is ".Y"
Defs file same name, ".H" extension.
Info file same name, ".I" extension.
Extended Tables in file "extable.[h1/h2/h3]".
Specifying -s switch also enables the -i switch