Vaulderie

From the White Wolf Wiki, the most complete White Wolf reference

Vaulderie is a blood rite practised by the Sabbat to bond pack members together. Each member of the pack drips a small amount of Vitae into a cup; a ritual is performed, and then the blood is shared amongst the pack.

The ritual produces a communal, weak blood bond called the vinculum. It generally makes pack members supportive of and loyal to each other, though it does not produce the extreme reactions of a full bond.