Standard unusual vs unusual. When opponent makes an artificial 2 suited call with suits known,

a cue of their lower suit shows limit plus values in our corresponding lower suit.

The same is true of their higher suit. Double of their artificial bid shows defense against one or both of their suits.

Other calls and raises are competitive or to play.

Exception 1© -(2NT) - 3¨ = to play in ª to allow opener © rebid. 3ª = force in this auction