incorrect mysqli_query return value? or documentation problem?

I apologize for troubling the list again, but I sent an email on the 5th
which has so far received no response. Archived here:
https://news-web.php.net/php.internals/112755

Put simply, the mysqli_query function does not return a boolean value as
the documentation says it should. Is this an error with mysqli_query or a
problem with the documentation? Or is the OPTIMIZE TABLE query beyond the
scope of standard SQL?