The term Guarding Block (daebi makgi) refers to a family of blocks used in ITF-style taekwondo. WTF-style taekwondo has no block called a Guarding Block, though blocks such as the Double Knifehand Block are similar.
Guarding Blocks are frequently used as a ready posture in free sparring, since one can position oneself in a half-facing posture and protect the body completely with both hands. Although the L Stance or Rear Foot Stances are most widely used, it can also be used with all other stances. The default hand position is a fist, but knifehands can be used as well.
The block: keep the blocking surface half facing the target at the moment of blocking. Bring the opposite knifehand or side fist in front of the chest 3 centimetres from the body. The guarding hands should be flexible enough to protect the whole body against an attack. Keep the body half facing the target at all times.