Muse is both a common term for a handheld Cognet linking device, and also a specific brand of said CogLink device. Functionally the Cosmic Era version of a smartphone
A horrific device only employed by the most black hearted of magic users.
More colloquially known as the avatar, muse, or handle.
Medieval Britons didn't write contracts. Instead, men making agreements would clap their knives onto an altar and recite the agreement three times to seal a deal. Even after the Normans introduced written contracts, British nobles would wrap the parchment around a knife to authenticate it.