Seeing as my comment is getting popular, I may as well give people the chance to vote on it.
I would recommend deleting the tab-key and tab tags. tabs makes sense, and we could make tab a synonym for it. Tabs are a useful GUI feature and I can imagine interesting questions that revolve around them.
The tab and tab-key tags seem useless to me. Why would we want a tag for a particular key on the keyboard? Granted it is one used extensively by those of us who regularly use shell autocompletion, but what kind of computer problem, that can be expressed as a question and answered on this site, would be tagged as tab?
From the looks of things tab/tabs is being used in various contexts
- browsers → browser-tabs
- spreadsheets → worksheet-tabs
- indenting and formatting → tab-key may fit best in these situations
- other application tabs such as Notepad++ tabs
As always, if you're going to retag a bunch, it's best if you also fix up other things wrong in the question. No need to bump a question and leave it fugly.