In addition to tagging by category (which you end up spending more time deleting tags), it would be great to include a filter as well. Currently if I only wanted to tag all VAV's on a floor, I need to create a schedule and select the rows, come back to the view and Tag all-selecting an appropriate tag. But what if you working with linked files? Method just described doesn't work. BUT, you can filter and make objects different colors, pattern, lines types via view filters with linked models. Am I getting through? You picking up what I'm putting down?