catplaystation - I believe the terminology exists for landing aircraft landing behind other landing aircraft only. The RT manual (CAP413) Sec 4-57 states:
A landing aircraft may be permitted to touch down before a preceding landing aircraft has vacated the runway provided that:
1. the runway is long enough to allow safe separation between the two aircraft and there is no evidence to indicate that braking may be adversely affected;
2. it is during daylight hours;
3. the preceding landing aircraft is not required to backtrack in order to vacate the runway;
4. the controller is satisfied that the landing aircraft will be able to see the preceding aircraft which has landed, clearly and continuously, until it has vacated the runway; and
5. the pilot of the following aircraft is warned. (Responsibility for ensuring adequate separation rests with the pilot of the following aircraft).
Example:
ATC: 'BIGJET 347, runway 28, land after the B737, wind calm'.
A/C: 'Land after the B737, BIGJET 347'.
I cannot find anywhere that says an aircraft will be cleared to land when there is an aircraft still taking-off.