[Oz Cello]

TH, you're right that the search doesn't seem to match text in the name of collections. Collections is also not listed in the first dropdown where you choose which field you're searching in. Maybe that's why there are no results from the names of collections? You can search the name of collections by going to the collections tab and using the search filter there. Not sure why it would be excluded from the main library search though. Might be an oversight.

In answer to Mike's question about which terms seem intuitive, I think 'any' is the only one you need. The 'mode' of the search takes care of the other options discussed. While you could use 'none' to mean 'no label assigned', that meaning wouldn't be clear from the word 'none' and the same result can be achieved by selecting 'unassigned' for the search mode. The same goes for using 'all' to mean 'has a label' - it would be ambiguous and would have the same effect as choosing 'assigned' for the search mode. I think 'any' is reasonably clear in meaning that no filtering is done for that group, but an alternative might be just to leave it blank when no filtering is applied. I can't think of a reason why 'any' should become 'none' in collections. It doesn't seem to behave any differently and should probably follow the same pattern as the other filters.