Yup, OR is already implicitly present, as far as I can tell. However, the lack of AND and NOT (or “-”) search filter operators in the main board view is one of the big showstopper personal productivity issues I have with kanboard (other than performance problems and Kanboard misinterpreting drag & drops as clicks on Firefox), without them it’s impossible to drill down tasks when you have a big backlog (for a “blogging pipeline” board, for example).
Various issues were reported there (and here) and there in the past, but those got closed in favor of the forum, considered feature requests rather than bugs.
The documentation at https://docs.kanboard.org/en/latest/user_guide/search.html hints that you can have a parameter multiple times, for example:
Multiple assignee lookup:
assignee:user1 assignee:"John Doe"
…but from what I’ve seen when using this with tag:foo tag:bar, this behaves as an OR search, rather than an AND, as I get results that have either one of those tags. I also tried these variants, which don’t work:
tag:foo AND tag:bar
tag:foo NOT tag:bar
tag:foo -tag:bar
tag:foo+bar
tag:foo,bar
It would be so nice if they did, as I’d like to be able to search for, say, things tagged with “blog” that are not tagged with “technology”.
I wish there was a way to crowdfund some of kanboard’s features or bugfixes like these…