Warren Veach said
1 year, 1 month ago: A good use of a tag might be, for example, I see something in one of your pictures that I think one of my friends might like to see or be interested in, so I tag him by commenting with a “@myfriend” in the comments to bring it to his attention.
Technically its not “tagging” in the common usage of the term, but IMHO its still tagging.