core + attic (Attic Area): these terms have been either depricated from the core or extentions, or removed from pending as not accepted into the full vocabulary.

boardingGroup

Canonical URL: http://schema.org/boardingGroup

Thing > Property > boardingGroup

The airline-specific indicator of boarding order / preference.

Usage: Fewer than 10 domains
Values expected to be one of these types
Text
Used on these types
FlightReservation

Schema Version 3.2