Arcane Mark

Some wielders of magic can create a mark made of magical energy that can be inscribed on objects or creatures. Stories and legends refer to these marks being used to signify that a specific person was trustworthy or that a particular item belonged to the caster and could be summoned to them.
A few very powerful wizards were said to shape their magic such that their mark was visibile in its working. A spell scroll for Tasha's Hideous Laughter, for example, might include the arcane mark for the archmage Tasha.