Initials, most likely fused together to make a sigil.
In those initials you'll find either the name of a daemon or a 'headmaster'.
Or if they've put some decent research into it, a phrase that catalyzes servitude and disassociation.
They are being literally branded so nothing is out of the picture..
It def. looks sigilic.
Occultfag here.
That, by itself, isn't a solid metric of our success.