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

requiresSubscription

Defined in the pending.schema.org extension.
Canonical URL: http://schema.org/requiresSubscription

Thing > Property > requiresSubscription

Indicates if use of the media require a subscription (either paid or free). Allowed values are true or false (note that an earlier version had 'yes', 'no').

Usage: Between 100 and 1000 domains
Values expected to be one of these types
Boolean
MediaSubscription
Used on these types
ActionAccessSpecification
MediaObject

Source

https://github.com/schemaorg/schemaorg/issues/1741

Schema Version 3.4