This is related to another request floating around, but this request is for AnkiDroid instead of the desktop app.
Current behavior
Custom study > Limit to particular tags
Select several tags. The custom study will include all of the cards which have any of the tags (set union / OR condition), but there is no way to limit it to cards which have all of the selected tags.
Desired behavior
There should be a way to limit the session to cards which have all of the selected tags (set intersection / AND condition).
It’s pretty straightforward to do this with a Filtered deck (which is just like Custom study, but you can choose whatever you want, instead of from a limited list of options). You can even create it through the Custom Study interface, and then edit the search filter to remove the "OR"s. Does Custom Study need to change when Filtered decks can already do what you need?
For some reason the UI wouldn’t let me include a link in my original post. The other request is here:
I saw filtered decks suggested before, but as far as I can tell this doesn’t work in AnikiDroid. The AnkiDroid filtered deck UI doesn’t seem to offer a way to filter on individual tags, or even to restrict the filtering to a single deck. Maybe I’m mistaken?
Thank you for the link! The responses to that suggestion are pretty much the same as what I gave you here. Filtered decks are the solution, and anything you can search for in the card browser, you can use as a search filter in a Filtered deck. It works the same on AnkiDroid as in Desktop. AnkiDroid User Manual
Thanks everyone. It looks like I can do what I wanted to using a filtered deck. That leads me to another question however.
If filtered decks can do everything that custom study does, then why does custom study exist? If custom study can do something that a filtered deck can’t, then perhaps this feature request is still legitimate?
As far as I know – Custom study is intended as a more convenient “point-and-click” method of creating a Filtered deck. The end result is the same. If you open the Options for a Custom study deck, you’ll see the search filter that was created from the Custom study dialog boxes.
The only Custom study features that you can’t exactly do with a Filtered deck are “Increase today’s new card limit” and “Increase today’s review card limit” – but those don’t create a deck an actual Custom study deck either. And you can do that easily with “Today only” limits in Deck Options instead.