They are listed as reserved words in MySQL documentation for any version from 5.0 and up (at least):
I think compablity with MySQL here is an even or a more valid/important concern here than standards' compliance.
This is actually a minor issue with standards in MySQL ( + derivates ) as compared to lots of other non-compliances IMO.
If standards should decide there would never have been MySQL!
Anyway it is not a big deal whether ON or OFF, I think.
But maybe the parser require them as reserved for some casesdue to imperfections in the parser itself? This could be why they were made reserved.
That sould at least be checked carefully before changing anything.
-- Peter
-- Webyog