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.

confirmationNumber

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

Thing > Property > identifier > confirmationNumber

A number that confirms the given order or payment has been received.
Values expected to be one of these types
Text
Used on these types
Invoice
Order
Super-properties
identifier

Schema Version 3.4