core + bib (Bibliographic Extension): terms relating to books and bibliography.

productID

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

Thing > Property > identifier > productID

The product identifier, such as ISBN. For example: meta itemprop="productID" content="isbn:123-456-789".

Usage: Between 100,000 and 250,000 domains
Values expected to be one of these types
Text
Used on these types
Product
Super-properties
identifier

Schema Version 3.3