The Additional Rules (Article 1, 2)

Article 1. The Definition and principle of the Additional Rules
  1.The Additional Rules are in place to solve especially difficult situations.
2.The Additional Rules are intended to come down on the side with the strongest claim using common Baduk logic. When this is not clear the situation must be played out.
3.If the Additional Rules are insufficient for a game position in a toumament, the KBA will adjudicate.

Article 2. Reinforcement
1)The last Kongbae (neutral point) and reinforcement
  In Figure 1 Black 3 is an efficient move as it will ahead to Bik (seki, a local stalemate)
  In Figure 2 If Black 2 is the last Kongbae, Black should indicate an intention to continue. If White gives up Chaksu, then Black may press an attack.

2)In Figure 3-1 If Black clearly has more Paegam (ko threats), Black A is not needed.
  In Figure 3-2 White 1 should be sufficient to capture all the Black stones. If white has clearly more Paegam no further move is need.

3)In Figure 4, white must play at A to achieve Bik because in this area Black has a strong claim.

4)In Figure 5, If the situation persists at the end of the game and neither player has any intention to play, than it is deemed to be Bik (a seki)