Rarely does Alpine Savvy post material directly from another website. But in this case I will, because it can't really be improved upon.

A similar rappel check acronym I’ve used is BARK (Buckle, Anchor, Rap device, Knot) but I was never quite satisfied with that one, because it left out securing the ends of the rope, and putting in an auto block. This new acronym nicely covers both of those.

The below content is straight from Climbing magazine

BRAKES - a system check for rappelling

Prior to rappelling, you should check every aspect of your system. The rappelling safety acronym BRAKES, developed by Cyril Shokoples in 2005 and now widely used by climbing schools, can easily be employed as a pre-rappel checklist. It’s a good idea to go through this list out loud by stating each letter and touching the part of the system you’re checking. Confirm with your partner when possible that each component of the system has been set up appropriately and is going to be applied correctly.

B – Buckles: Check the buckles on your harness. Make sure they are snug and that all appropriate straps are doubled-back.

R – Rappel Device/Ropes: Check that the carabiner attached to your device is locked, both strands of the rope have been loaded correctly in the device, and the rope is properly threaded through the rappel anchor.

A – Anchor: Confirm that the anchor is strong. If it’s a tree, make sure it’s alive, large enough to hold your weight, and that it has a good root base. If it’s a boulder, ensure that it is not going to move. If rappelling off bolts or gear, confirm that they are suitably strong enough. Double-check that any webbing or cord isn’t damaged or too faded.

K – Knots: Check all the knots in the system. Make sure that knots adjoining two ropes in a double-rope rappel are correctly tied with enough tail.

E – Ends: Confirm that the ends of your ropes are on the ground or that they reach the next anchor. Confirm that your system is closed with knots at the end of your rappel lines.

S – Safety Backup/Sharp Edges: Use an autoblock backup and check to make sure that you aren’t going to rappel over any sharp edges.