To add a tag, go to the candidate's profile and under Tags, simply type in the tag you want to use or choose a previously used one from the drop down list. The tags are automatically placed in A-Z order and forced to lower case. There's no limitation to the number of tags you add!
Bulk add tags
You can add tags on several candidates at the same time. To do so, enable the Bulk selector (1), select the candidates you want to tag (2), click the three buttons (...) in the menu (3) and then Tag. All inserted tags will be added to all selected candidates.
Filter on tags
After you've added tags, you might want to be able to find all candidates with this tag.
In job process
To filter on all candidates with tag/tags in a specific job process, open the Filter (1) and add the tags (2). You'll then see all candidates with that tag in that process.
From Candidate bank
You can also filter on the tags in your entire candidate bank. To do so, go to the tab Candidates, open the filter (1) and select the relevant tags under Tags (2).