Vincre's Mark

Vincre's mark is a Deathly Hallows sign with a green snake coiled around it. It shows that the bearer is working for Vienna. Like the Dark Mark, it is branded into the left wrist, but unlike the Dark Mark, even if Vienna died, it would not fade.

Symbolizes...
The Mark symbolizes Grindelwald's failed quest for the Deathly Hallows, and the viper, which Vienna believes is sacred. It honours Grindelwald and Salzar Slytherin at the same time, as Vienna had always respected Salzar Slytherin.