You can specify the pattern save file in the local variables
section at the end of a file, but before a hi-lock mode specification,
like here:

Local Variables:
hi-lock-patterns-file: "patterns.txt"
mode: hi-lock
End:


Several files can share one pattern file.  The example completely
substitutes file local patterns, if you want to use them at the same
time, it will become more complicated.  If you don't bind
`hi-lock-patterns-file', the behavior is like before.


Regards,

Michael.