In Release 9.0 a new /size property was published (see issue #2587) to model product sizes as free-form text.

As a follow-up to address the still open items from issue #2587 and in collaboration with @danbri and @mfhepp we are now proposing to also allow a more structured way of specifying product sizes.

For example, apparel sizes are often expressed as a combination of one or more of the following attributes:

• a size system, typically a country, region, or standard identifier (e.g., "eu", "iso 8559").
• a size group (e.g., "big and tall", "petite"), typically used together with age group and gender information to identify a fashion department.
• A size code (per the size system and size group), for example "3XL" or "32Wx34L".
• one or more manufacturer-defined measurements of the product (e.g. for pants: "waist" with a measurement of 32 inches and "inseam" with a measurement of 34 inches).
• one or more (ranges of) measurement(s) for the intended consumer (e.g. "waist" between 30 and 32 inches and "inseam" between 33 and 35 inches).

We propose to add a few new types and properties to model these size-related attributes, building on prior art such as the GS1 Web Vocabulary (SizeDetails) and the CPI Ontology (example, reference).

We also propose to generalize the concept of a "measurement" since it applies to many types of products (i.e., not just wearables). For example a bicycle has wheel and frame measurements, and a screw has gauge and thread-distance measurements.

Given the size of the proposal, an external Google Docs document is created for review and inline comments.

Adding @mgh128 and @jvandriel based on the discussion in #2587.