Yes, finally, really ignoring hints – but it’s a sort of bug, of course.
In the upgrade from 9i to 10g there was a change in the “hint parser”. If you put a valid SQL keyword inside the hint delimiters (the note says /*+ */ but doesn’t mention the –+ alternative for specifying a hint, thought it’s probably still true there) when the keyword is not a valid hint – for example the word NOLOGGING which I have seen people use as if it were a hint – then Oracle will ignore all the hints.
Earlier versions of Oracle simply noticed that you had embedded something that wasn’t a valid hint, but that didn’t stop the parser from reading the rest of the hints correctly.
If the invalid hint is not a valid SQL keyword then there are no nasty side effects.
This might explain why I ran into an odd problem a little while ago when I added a comment to my hint list and found that the hints stopped working. I can’t remember the exact details any more but I think my comment was something along the lines of: “Do not … because …”, and this broke the hints until I changed it to “Don’t … because …”.