For years, it has been possible to add tags to questions in the question bank. Then in Moodle 3.5 (thanks to the MUA) it became possible to use tags to randomly select questions to fo into quizzes.
Then, in Moodle 3.6 we added the ability for questions and categories to have an idnumber (because we wanted it for the Embed questions filter).
However, until now, those things have not been displayed in the question-bank interace, which makes it more difficult than necesasry to organise things.
I dicided to have a go at fixing that, and here is what I have managed so far. Comments welcome
Also, when adding questions to the quiz:
and when editing the list of question categories:
(In case you are wondering, 0 is not a sensible idnumber for a category. However, it is a good way to find bugs like MDL-66796. Also, while working on this I discovered MDL-66801. Three fixes for the price of one, I hope!)