I'm working with multiple tickets in RTC and have so far successfully multi-updated fields like filed against, status etc. However I see no option to multi-update the tags field.
I have hundreds of tickets I need to add tags to. Is there a way of doing a multi-update on these?
It is currently missing feature in RTC web interface. See Enhancement 219534: add support for bulk edit of attribute "Tags" in work items on Web. Anyway it is possible in Eclipse client. You can try it.