Binding Link

Binding link used by Meg on Sam.

A binding link is a symbol which keeps a demons or any other possessing entity trapped inside its meatsuit i.e. the human it is possessing. The demon can neither escape voluntarily or be exorcised. A binding link may be related to the "binding magic" used on curse boxes to keep the evil inside.

Episodes

2.14 Born Under a Bad Sign

When Meg possesses Sam she brands a binding link into his forearm. When Bobby tries to exorcise her, it doesn't work. Bobby realizes the brand is keeping the demon trapped inside Sam, and burns across the mark with a hot poker, breaking the spell.

5.20 The Devil You Know

Crowley carves a symbol into Brady's chest while they try and convince him to help them.

Crowley: This bit of carving will tie our friend here down. No zapping off, locked in the meat suit. An important part of our bargaining strategy.

6.10 Caged Heat

Handcuffs with binding sigils etched into them.

Meg tries to leave her host, but Crowley has worked some form of binding magic to prevent demons inside his monster prison from leaving their bodies.

8.22 Clip Show

While going through old Men of Letters records, trying to figure out a way to cure a demon for the third trial. Sam finds a film reel, which showed a demon chained up in shackles with various binding sigils etched into them, go through a failed exorcism in an attempt to cure the demon.

8.23 Sacrifice

Sam and Dean use a pair handcuffs that have been etched with various sigils to keep Crowley from smoking out of his meatsuit or teleporting away.

9.03 I'm No Angel

Sam and Dean use the binding handcuffs on the rogue reaper Maurice, as a means to extract information from him.

9.10 Road Trip

Crowley is freed from the Men of Letters dungeon, to help expel Gadreel from Sam's body, but only on the condition he needs to wear the binding handcuffs. Crowley also wears a collar that apparently serves the same purpose as he can't leave his meatsuit with it on.