Pass For Ko
A "pass for a particular ko" is a special move type, used in Japanese Rules during hypothetical play for dispute settlement. The rules state that in the move sequences considered for that purpose, retaking a ko (that the opponent took earlier in the sequence) is not allowed like in normal play. Instead of playing regular ko threats, a player can only regain the right to recapture in that ko after making a pass for that particular ko (giving the opponent an extra opportunity to win the ko).
This rule is used to determine life and death without letting different kos influence each other, and without allowing groups to rely on ko threats for their survival.
(It is not clear if later recaptures by the same player in the same ko require further passes for that ko, or if this regained right to recapture in that ko is permanent and normal ko threats are sufficient there afterwards.)
See also PassAsKoThreat