Beat to Windward Definition

Regarding the new Cutter Rig definitions in the IRC Rule, when is a boat ‘on a beat to windward’?

ISAF CASE 132
Rule 18.1(a), Mark-Room: When Rule 18 Applies
Rule 42.3(c), Propulsion: Exceptions
A boat is ‘on a beat to windward’ when the course she would sail to finish as soon as possible in the absence of all other boats is a close-hauled course or above.

Question
The phrase ‘on a beat to windward’ is used in rules 18.1(a) and 42.3(c). When is a boat on a beat to windward?

Answer
For the purposes of rules 18.1(a) and 42.3(c), a boat is on a beat to windward when the course she would sail to finish as soon as possible in the absence of all other boats is a close-hauled course or above.
When a boat is on a windward leg, she is not necessarily on a beat to windward. An example is a boat that has overstood a windward mark and, in the absence of other boats, would therefore sail below close-hauled to finish as soon as possible. Such a boat may have overstood the mark either by sailing beyond the layline to the mark or because a change in wind direction has made it possible for her to sail to the mark on a course below close-hauled.
Also, when a boat is on a reaching or a downwind leg, there are circumstances in which she may be on a beat to windward. This can happen when a boat has been swept by current below the rhumb-line to a reaching mark, or there has been a change in wind direction, and as a result the course the boat would sail to finish as soon as possible in the absence of other boats has become a close-hauled course or above.

ISAF 2013