The history of leaving an individual mark behind reaches back to at least the Palaeolithic age, when early humans left negative imprints of their hands on the walls of caves. These negative handprints were produced by blowing pigment onto one hand, so that its life-sized outline would stay visible.1 In past societies with developed writing systems, such as ancient Egypt, Greece, and the Roman Empire, written name tags would appear on man-made and natural surroundings, such as the walls and floors of buildings or caves as well as on rocks or trees.2 Even if a name was not always unique, it was a person's official identifier and therefore the personal mark left behind most frequently. In the same literate societies, however, we also find handprints left as personal traces3--like the written tags of the same eras, these were either incised into a surface with sharp stones or metal writing implements, or drawn in colour. Apparently, these hands, as a kind of physical imprint, were understood as individual markers in the same way as name tags and portrait sketches (which sometimes bore the addition of a name), even if they occur much more rarely than their written counterparts in Roman times. This paper was presented at the international conference "Tag. Name Writing in Public Space" at the John-F.-Kennedy Institut, Freie Universitat Berlin in September 2017. The event centred neither on personal marks nor graffiti in general, however, but on the practice of tagging. Tagging is part of modern graffiti culture, and tags--informal, non-commissioned inscriptions of names by visitors, passers-by, and inhabitants--form a large part of historical graffiti as well. The term graffiti is, nonetheless, a problematic one when one regards the diverse practices and forms to which it is usually applied and the eras they span (from historical graffiti to modern street art). The tags therefore represent an appropriate selection to avoid or minimalise the methodological difficulties in bringing together material from different cultures and times. This essay deals with one of the few large collections of ancient graffiti we possess: those from the ancient Roman city of Pompeii, situated in the region of Campania on the southwestern coast of Italy.