the question is in the title
I’m talking tags like here on Discourse, like #jira and #tickets right above this post
I’m specifically looking to group a couple mobile-related issues from multiple projects, CB-456 and LB-1102, that way any developers looking to improve the mobile experience can find them more easily~
although, if tags like this aren’t wanted/needed, I’d like to know as well before I start adding a bunch of tags to tickets I come across… 
It’s the “labels” field on Jira where you can add arbitrary tags. But I don’t know if everyone can edit them.
Also how and if they are used for sure depends a lot on the project. But for example for Picard I do use them for some tags.
that’s what I thought that field was. I can add them to existing tickets, from what I can tell
as implied (but not said) in my initial post, this would be a cross-project label, since it can apply to anything with a mobile interface, similar to how good-first-bug seems to be used
I’ll go ahead and add the label to the two tickets I linked