This read-write enumeration (mapCLP(1), setCLPzero(2), setCLPone(3)) controls how the Frame Relay DE bit is translated to the ATM CLP bit; cases 2 and 3 ignore the incoming DE bit entirely and force CLP to a fixed value, and on FRSM12 cards mapCLP should not be used when chanType is frForward. An administrator chooses mapCLP to let discard-eligibility follow the actual DE marking on incoming frames, or chooses setCLPzero/setCLPone to force a constant cell-loss-priority regardless of DE. For example, on an FRSM12 channel configured as frForward, an administrator must avoid mapCLP and instead use setCLPzero or setCLPone per the object's documented restriction for that chanType.