DefinedTerm Schema is layer 4 of the Entity Architecture and Governance Framework (EP-9). It requires JSON-LD using the DefinedTerm or Service type, with a description that matches the page text 100 percent word for word. It is mandatory, with zero schema errors.
What layer 4 covers
Layer 4 covers the machine-readable declaration of an entity. EP-9 requires a JSON-LD block of the DefinedTerm or Service type, inside an @graph, with stable @id references and a description that repeats the visible definition word for word. Schema confirms an entity that the page already shows; it does not create one.
This follows Google's general structured data guidelines, which require markup to describe content that is visible to users. A description that says more, or something different, than the page is the kind of mismatch those guidelines exclude.
Choosing DefinedTerm or Service
Choosing between DefinedTerm and Service depends on the entity group. A method, a concept or a problem is a term with a definition, so it is declared as a DefinedTerm inside a DefinedTermSet. An offer that a buyer can purchase is declared as a Service with its provider.
The framework's own master page shows the pattern: a WebPage about the entity, a DefinedTerm with the canonical definition, and a DefinedTermSet for the framework, all linked by @id.
Validating the schema
Validating the schema has two parts, syntax and parity. Checkpoint CHK-EP-06 requires zero syntax errors, and CHK-EP-07 requires the schema description to match the rendered text exactly. The second check is done by comparing the two strings, because no validator reads the page for meaning.
Google's Rich Results Test reports on the types that Google uses for rich results. DefinedTerm is not one of them, so also run the page through the Schema Markup Validator, which checks every schema.org type.
Should I use DefinedTerm or Service?
Use DefinedTerm for a concept, method or term with a formal definition, and Service for an offer that is delivered to a customer. Schema.org defines DefinedTerm as a word, name or phrase with a formal definition, and Service as a service provided by an organization.
What does the EP-9 schema template contain?
The EP-9 template is one @graph block with three nodes: a WebPage for the page, a DefinedTerm for the entity with its definition, and a DefinedTermSet for the framework that carries sameAs to the DOI. The nodes reference each other by @id.
Checkpoints for layer 4
The checkpoints for layer 4 test the schema for syntax errors and compare its description with the rendered page text. Both must pass for the layer to pass. They are taken from the 15-point EP-9 technical audit checklist and keep their original identifiers, so an audit report can cite each one directly.
| Checklist ID | Audit layer | Mandatory verification requirement | Tool and method |
|---|---|---|---|
| CHK-EP-06 | L4 Schema Syntax | Valid DefinedTerm / Service JSON-LD schema with 0 syntax errors. | Rich Results Test |
| CHK-EP-07 | L4 DOM Parity | Schema description matches rendered HTML text 100% word-for-word. | Tier 3 DOM QA |
Treat a single changed word between the schema and the page as a failure. Edit the definition in one place and copy it to the other, so the two never drift apart.