A label attached so a thing can be found among others. A tag is added by a reader as often as by an author.
Middle English tagge (a small hanging piece, a tag on a lace end), probably of Scandinavian origin; a label attached so a thing can be found among others keeps the old sense of something small fastened onto a larger piece.
A label attached so a thing can be found among others. It is added by a reader as often as it is added by whoever made the thing in the first place.