In short. Schema.org citation describes references attached to creative works, with CreativeWork or Text as expected values.

Definition: Schema.org's citation property describes a citation or reference to another creative work, including a publication, web page or scholarly article. It attaches that reference to the work containing it and accepts a description of a creative work or a text value.

Key facts

Schema.org's citation definition lists CreativeWork as the type on which the property is used and CreativeWork or Text as expected values.
A CreativeWork is Schema.org's general type for creative works, including books and photographs.
Schema.org's data model allows properties to have multiple values, represented as an array in JSON-LD.
The Schema.org Markup Validator documentation describes checking markup supplied directly or fetched from a page URL.

What relationship does citation describe?

The relationship runs from the work containing a reference to the work being referenced. For example, Schema.org's property definition explicitly includes a reference to a web page; the referenced material can therefore be an ordinary website document.

The CreativeWork documentation also defines isBasedOn, which describes a resource from which a work is derived, modified or adapted. A reference and an adaptation express different relationships, so the choice of property follows the relationship described in the content.

A text value can carry a bibliographic reference. A CreativeWork object can describe the referenced work using named fields: the same documentation defines name as the item's name and url as its URL.

How can the reference be written?

JSON-LD is a structured-data format supported by Schema.org's data model. This illustrative fragment describes this entry's reference to the Schema.org citation documentation, using the expected CreativeWork value type:

{
  "@context": "https://schema.org",
  "@type": "CreativeWork",
  "name": "Schema.org citation property",
  "citation": {
    "@type": "CreativeWork",
    "name": "citation",
    "url": "https://schema.org/citation"
  }
}

The outer object represents the work containing the reference. The nested object identifies the referenced document. For several references, the same data model permits an array of values under citation; those values form an unordered set by default, so their position alone carries no explicit bibliography order.

What does this mean for AI search?

As of 17 October 2026, Google's AI features documentation states that AI Overviews and AI Mode require no special Schema.org structured data. It specifies that a page must be indexed and eligible for a Google Search snippet to qualify as a supporting link.

Whether an answer engine uses citation when selecting sources is not established by these documents. The property's documented purpose is to describe references attached to creative works.

How is the markup checked?

The Schema.org Markup Validator extracts structured data, displays a summary of the resulting graph and identifies syntax mistakes. Review the extracted graph to check that citation belongs to the work containing the reference and that its value describes the intended source.

Google's structured-data guidelines require markup to represent the page's content accurately and cover content visible to readers. Applied to references, this calls for keeping the structured description aligned with the reference presented on the page.

FAQ

Can you use a plain-text reference?

Yes. Schema.org's citation definition explicitly includes Text among its expected value types. A nested CreativeWork object is another documented option.

How can you include several references?

Use an array of values in JSON-LD. Schema.org's data model permits multiple property values and treats them as unordered by default.

Sources

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