Green’s Dictionary of Slang

tag v.2

also tag up
[tag n.3 (8)]

(orig. US) of graffiti artists, to affix one’s name to a picture, a wall etc; thus tagging n.

[US]Honolulu Star-Bulletin (HI) 7 Feb. 7/6: The eyesore of ‘tagging’.
[Ire]J. Healy Streets Above Us (1991) 184: Graffiti, murals, spray-can art, tagging, bossing.
[US]Dr Dre ‘Some L.A. Shit’ 🎵 Taggin, hittin fools up / Ditchin my class, just to fuck yo’ school up.
[US]W. Shaw Westsiders 25: A graffiti artist is tagging the name of his favourite artist on a freeway wall.
[US]J. Lethem Fortress of Solitude 173: Check it out, man, he’s tagging up.
[UK]R. Milward Apples (2023) 32: [She] always had a Pilot marker on her and she tagged her name round the garden.
Dly Press (Newport News, VA) 24 June A9/2: Signs of gang activity — mainly tagging with graffitti.
Californian (Salinas, CA) 5 July A8/1: A witness called to report [...] a man ‘tagging’ a bridge.
[UK]G. Krauze What They Was 16: The post office [is] tagged up with black spray paint .

In compounds

tagging crew (n.)

a gang of graffiti artists working as a team.

[US](con. 1982–6) T. Williams Cocaine Kids (1990) 60: We were a tagging crew [graffiti artists].
[US]G. Sikes 8 Ball Chicks (1998) 260: Annie grew even more committed to her tagging crew.
[US]L.A. Times 25 June A8/1: All those arrested [...] were involved in the tagging crew.
Californian (Salinas, CA) 5 July A8/1: Tagging crews commonly refer to themselves as artists.