Product structured data, and what it cannot do

01

What markup states

Applies to marketplace onlyown storefronthybrid

A product page is prose and pictures. A system reading it has to determine which number is the price, whether “one left” refers to stock or is promotional copy, and whether a paragraph about a scratch describes this unit or the model in general. Structured data states those facts in named fields alongside the page, so the reading does not depend on inference.

That is the mechanism in full. Its effect scales with how ambiguous the page would otherwise be, and a page for one-of-one resale stock carrying condition notes and item-specific defects contains more of that ambiguity than a page for a replenishable manufactured product.

02

The thing and the terms are separate vocabularies

Applies to marketplace onlyown storefronthybrid

The vocabularies divide the facts explicitly. A product is a described thing carrying properties such as name, brand, model, and images.¹ An offer carries the commercial terms under which it is sold — price, currency, availability, and the conditions of sale — so availability is a property of the offer rather than of the object.²

The third column is a maintenance schedule. The frequently changing fields are all on the Offer side, which identifies the part of the markup that needs a refresh path and the part that can be written once.

03

Three fields that behave differently for one unit

Applies to marketplace onlyown storefronthybrid

Markup guidance is generally written for replenishable goods carrying manufacturer identifiers. Three fields therefore need different handling for resale stock.

• Identifiers. A vintage or handmade item often has no GTIN and no applicable MPN. An omitted field states that no such identifier exists; a substituted one states an identifier that belongs to a different product and can collide with it.
• Condition. The vocabulary supplies an enumerated condition value, which names a bucket. The specific defect goes in the description, where it can be read.
• Quantity and availability. With one unit the move from available to sold is single and total, so the value is accurate for exactly as long as the refresh path keeps it accurate.

The identifier field is the one a bulk tool is most likely to populate because it looks required. An empty field is accurate for a unique object. A borrowed value is a statement about a different product that a machine reader will act on.

04

What image properties assert

Applies to marketplace onlyown storefronthybrid

Image properties belong to the product vocabulary and take multiple images with stable URLs, showing this unit rather than the model. Google documents Product structured data with its own image expectations for search eligibility, which are stated requirements for that eligibility.³

An image does not assert a readable fact. A photograph of a scratched lens barrel is evidence to a person and pixels to a field-reading system. Where a defect affects the sale, it exists in text as well as in the photograph, since a dispute over disclosure turns on what the listing said rather than on what an image showed.

05

Questions the markup leaves to other systems

Applies to marketplace onlyown storefronthybrid

Correct markup is a set of statements about a page. The table records what those statements do not cover.

The fourth row has a practical consequence. Publishing markup places the availability figure in a machine-readable field that another system may read and cache, so the accuracy of that field matters more once it is published than it did when the same figure appeared only in prose.

06

Validate the syntax, then check the values

Applies to marketplace onlyown storefronthybrid

Publishing markup has two parts. Validation confirms the syntax parses and the required fields are present. It does not confirm the values are true today.

1. Validate the markup on a representative page and resolve structural errors first.
2. Check each value against the system of record rather than against the page it was copied from.
3. Decide which fields may change without a corresponding markup update, and record the decision.
4. Re-run the check after any template change, since the markup is generated by the template and can be emptied by an unrelated edit.

Run on the camera’s page, the second part produces five lines, two of which do not resolve to a checked value.

The last row identifies the open item: until something updates that value when the object sells, its accuracy depends on a manual step, and the value is being published in a field other systems can read.

The fourth step covers the common regression, where markup that was correct at launch is removed by a later template change that nobody associated with it.

07

The documented position on markup

Applies to marketplace onlyown storefronthybrid

The Product vocabulary describes the thing and its images,¹ and the Offer vocabulary carries price, currency, availability, and conditions of sale.² Google documents Product structured data with image expectations attached to search eligibility.³

None of those documents describes how a page is selected for display, how a store becomes eligible for a checkout surface, or how a published availability value is kept current. Those are set elsewhere, and the markup carries whatever value the page holds at the time it is read.