Structured data that shows where a fact came from

Markup states, it does not verify

Structured data is a way to say what a value on a page is: a name, a part number, a dimension, a price. A machine that reads it does not have to guess from the layout. That is useful and limited. Markup that says a width is 36 inches is still wrong if the width is 35. Whether a value is trustworthy is a separate question, and the vocabulary is wider than most implementations use.

What Product markup can carry

• Identity: name, brand, manufacturer, and the identifiers sku, mpn and gtin, kept distinct.
• Measured properties: additionalProperty with a name, a value and a unit code, so a dimension has a unit instead of living in a sentence.
• Relations: a part that is an accessory or spare for another, or a consumable for it, stated rather than implied.
• Offers: price and availability, with the date through which a price is valid.
• Dates: when the page or the record was last modified.

An illustrative block

The values are invented to show shape. They describe no real product.

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Casement window unit, series ABC",
  "brand": { "@type": "Brand", "name": "Example Windows" },
  "mpn": "ABC-3040-R2",
  "sku": "D-ABC30R2",
  "additionalProperty": [
    { "@type": "PropertyValue", "name": "Unit width (frame basis)", "value": 36, "unitCode": "INH" },
    { "@type": "PropertyValue", "name": "Rough opening width", "value": 36.5, "unitCode": "INH" }
  ],
  "isRelatedTo": { "@type": "Product", "mpn": "ABC-3040-R1", "description": "Superseded by this revision" },
  "offers": {
    "@type": "Offer",
    "availability": "https://schema.org/InStock",
    "priceValidUntil": "2026-12-31"
  },
  "dateModified": "2026-10-16"
}

Where the source still has no home

The vocabulary has no standard field for who confirmed a value, or which source system it came from. A page can state the modification date and an identifier. The rest has to live in a record the page points to, and the page and the record have to be generated from the same place so they cannot drift.

Generating the markup from the checked record, rather than writing it by hand per page, is the practical rule. The values, units and dates in the markup are then the record's, and a comparison against every public copy shows where a page, a feed or a directory differs from it.

Organizations and locations

The same applies to the company. Organization and location markup can carry legal name, identifiers, departments, parent and subsidiary relationships and the lines carried. In a dealer network, those relationships tell a machine which record is the parent and which is a branch, which is part of resolving duplicate entities.

The record behind it is described in Business Truth.

Questions