For the first case, 'As Couples' is heard first, so you work As Couples to do the call 'Once Removed Latch On'. See diagrams below. EN: 40

For the second case, 'Once Removed' is heard first, so you work Once Removed to do the call 'As Couples Latch On'. Note that, for this case, the dancers in the set {, , , } are on every other plane in both the starting formation and the ending formation. Similarly, so are the dancers in the set {, , , }. EN: 60