How to add tags to multiple test cases?

Hi,

we have TFS 12.0.31101.0 installed. Is it a way to add tags for several test cases at once?

when selecting several test and using Edit Test Cases option - there is not Tags in field list:

and if I'm trying to type "Tags" manually in Filed textbox - the OK button remains disabled.

Is it a simple way to add same tag to all test cases in test suite?

thanks a lot