i'd like to know the same ... but not just for tags ... the other fields too. thanks.

Search for "tag:x AND NOT tag:y" or "name:x AND NOT name:y"

More help: http://www.rememberthemilk.com/help/answers/search/advanced.rtm

Is OR NOT a valid operator?

OR NOT are two operators, both valid. AND NOT can be written NOT as pointed out in another thread by bzpilman.

rajjan — Thank you! "NOT" (written alone) is exactly what I needed.

I have a very specific method for creating new tasks, which involves several elements. My goal is to create a search that identifies tasks which don't meet all the necessary criteria.

1. missing name prefix — NOT name:ABC
2. missing a tag — isTagged:false
3. missing due date — due:never

My previous attempt isTagged:false OR due:never OR NOT name:ABC obviously didn't work. Unless NOT name:ABC comes first, it's evidently impossible to perform this search. The correct (and successful) solution is:

NOT name:ABC OR isTagged:false OR due:never

So, problem solved. I would think, though, that you should be able to conduct a search like this in any sequence.

I also have had problems with NOT. Try to add () around the NOT-part, I've found that that helps at times.

emily, if you'e reading this, could we (you guys at RTM, i mean) stick this NOT option in the expanded advnaced search section for those of us who don't have these little codes memorized? thanks!

It's already at the bottom of the list showing advanced searches.

hmmm ... maybe we could stick a link to that page that rajjan refernced within the advanced search options page.