At present, '... filtering ... uses case-insensitive "contains" comparison.' However, every time I have wanted to use this function it has been to filter
(i.e. hide) a specific choice. So I either write some code to pick the seven values (out of eight) which I don't want to filter out (which requires maintenance if I ever amend the choice list) or I just give up. Can we have an extra argument, please, to make it keep all the choice
the matching ones? And it would be even better if it could use a regexp rather than a list of strings.