While acknowledging the fact that, sometimes, Britain does it differently .... what regulatory process requires this purported requirement ?
If there is no stopway/clearway, then one would expect TODA=TORA.
The statements
(a) "when no stopway or clearway is available the take-off distance must not exceed 1.25 x TORA" doesn't make much sense as it would infer having TODR>TODA
(b) "the take-off distance should not exceed 80% of TORA" likewise doesn't make much sense as it infers that we are not going to use a substantial fraction of the TODA.
.. or is this a misguided way to test knowledge of the airports design process which typically limits the amount of clearway ?
(signed) Confused