What?
Allows to define the physical cabins used by an airline. Two real world examples:
- On short-/medium-haul flights, eco and business typically share the same cabin, with merely a “moveable curtain” separating the two depending on demand (see Nesting). So one cabin for two service classes.
- Some carriers have introduced different First Class products (“regular” and “suites”). So two cabins for one service class.
Why?
Helps to realise the very real use-case of a moveable curtain. Might actually make the introduction of an explicit Premium Economy obsolete (or at least less urgent) as this could be tackled via dedicated booking classes.
When?
Depends on Custom Booking Classes and Nesting (of booking classes).