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.

caption

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

Thing > Property > caption

The caption for this object.

Usage: Between 50,000 and 100,000 domains
Values expected to be one of these types
Text
Used on these types
ImageObject
VideoObject

Schema Version 3.3