WebMEM™

The Protocol for Structuring, Delivering, and Conditioning Trust-Scored AI Memory on the Open Web

DefinedTermFragment

Part of the WebMEM® Protocol
Fragment Class: DefinedTermFragment
Location: /protocol/fragments/definedtermfragment/
Status: Current Draft
Last Updated: 2026-08-24

Overview

A DefinedTermFragment is a WebMEM fragment class for publishing the canonical meaning of a defined term within a specified semantic context.

It associates a stable term identity with its name, definition, provenance, namespace or glossary scope, and related terms where applicable.

A DefinedTermFragment allows a publisher to state explicitly what a term means rather than requiring a machine to infer that meaning from surrounding prose or general usage.

Unlike a DataFragment, which represents factual knowledge about an entity or context, a DefinedTermFragment represents the meaning of a term.

This makes DefinedTermFragment useful wherever consistent terminology is necessary for interpreting facts, fragments, entities, relationships, or resolution structures across a WebMEM implementation.

Semantic Purpose

The semantic purpose of a DefinedTermFragment is to state:

Within this defined semantic context, this identifier represents this term, and this is its intended meaning.

A DefinedTermFragment may establish:

  • the canonical identity of the term;
  • the human-readable name of the term;
  • the term’s definition;
  • the semantic namespace or glossary to which the term belongs;
  • the publisher responsible for the definition;
  • the provenance of the definition;
  • relationships to other defined terms;
  • and other contextual information required to interpret the term consistently.

The fragment provides a stable semantic reference that other WebMEM knowledge objects may use when the meaning of a field, concept, category, or relationship requires explicit definition.

DefinedTermFragment Within an SDT

A DefinedTermFragment exists as one modular knowledge object within a Semantic Data Template (SDT).

The relationship is:

Web Resource → SDT → DefinedTermFragment → Defined Term

An SDT may contain one or more DefinedTermFragments when terminology used by the resource requires explicit machine-readable definition.

Defined terms may also participate in broader glossary structures represented by a GlossaryFragment.

The DefinedTermFragment represents the individual term. The GlossaryFragment represents a structured collection or semantic context containing multiple terms.

DefinedTermFragment Requirements

A conforming DefinedTermFragment should establish enough information to identify the term and interpret its meaning within the intended semantic context.

Element Purpose
Fragment Class Identifies the knowledge object as a DefinedTermFragment.
Fragment ID Provides a stable identifier for the fragment within the published knowledge structure.
Term ID Provides a stable identity for the defined term itself.
Term Name Provides the human-readable name or label of the term.
Definition States the canonical meaning assigned to the term within the defined semantic context.
Semantic Scope Identifies the glossary, namespace, domain, vocabulary, or other context within which the definition applies when such scope is required.
Provenance Identifies or references the source, publisher, or lineage supporting the definition.

Additional information may be included when required by the domain, glossary, relationship model, or applicable conformance profile.

Term Identity

A defined term should have a stable identity that is distinct from its display label.

For example, a publisher might identify a term as:

webmem:machine_fact_object

while presenting its human-readable name as:

Machine Fact Object

This distinction allows the displayed terminology to remain human-readable while giving machines a stable identifier through which the term can be referenced across fragments and resources.

A term identifier should remain stable when practical, even if explanatory language surrounding the term changes over time.

Canonical Definition

The definition is the central knowledge object within a DefinedTermFragment.

A definition should state the intended meaning of the term clearly enough to distinguish it from related or potentially ambiguous concepts.

For example:

A Machine Fact Object is an atomic factual unit within a WebMEM fragment.

The purpose of the definition is not necessarily to provide a complete explanation of the concept. Longer explanatory material may be represented separately using an ExplainerFragment.

The DefinedTermFragment establishes what the term means. An ExplainerFragment may provide additional information about how the concept works, why it matters, or how it should be understood or applied.

Semantic Scope

A DefinedTermFragment may establish a semantic scope when the meaning of a term depends on a particular domain, glossary, vocabulary, organization, or publishing context.

Semantic scope helps distinguish terms that may have different meanings in different domains.

For example, the word resolution has many general meanings. Within the WebMEM Protocol, the term may be assigned a specific definition describing the process of moving from an identifier, entity, collection, or context toward a sufficiently precise information object.

Explicit semantic scope allows that definition to remain associated with the domain in which it is intended to apply.

Related Terms

A DefinedTermFragment may identify relationships to other defined terms.

Related terms can help establish the semantic neighborhood in which a term belongs and make explicit relationships that the publisher already knows.

Examples may include:

  • broader concepts;
  • narrower concepts;
  • closely related terms;
  • prerequisite concepts;
  • alternate or historical terminology;
  • or other explicitly defined semantic relationships.

Related-term references should use stable term identities where available.

The existence of a relationship should not imply equivalence unless equivalence is explicitly declared.

Example DefinedTermFragment

The following example represents the WebMEM term Machine Fact Object using the current HTML serialization.

<template
  data-webmem-fragment
  data-fragment-class="DefinedTermFragment"
  data-fragment-id="defined-term-machine-fact-object">

  <section
    data-entity-type="DefinedTerm"
    data-entity-id="webmem:machine_fact_object"
    data-semantic-scope="webmem">

    <span data-role="term-name">
      Machine Fact Object
    </span>

    <p data-role="definition">
      An atomic factual unit within a WebMEM fragment.
    </p>

    <ul data-role="related-terms">

      <li data-term-id="webmem:fragment">
        WebMEM Fragment
      </li>

      <li data-term-id="webmem:sdt">
        Semantic Data Template
      </li>

      <li data-term-id="webmem:provenance">
        Provenance
      </li>

    </ul>

    <meta
      data-role="provenance-ref"
      content="#provenance-webmem-protocol">

  </section>

</template>

The fragment establishes that:

  • the knowledge object is a DefinedTermFragment;
  • the term has the stable identity webmem:machine_fact_object;
  • the term belongs to the WebMEM semantic context;
  • its canonical name is Machine Fact Object;
  • its canonical definition is explicitly published;
  • related WebMEM terms are identified;
  • and provenance for the definition can be resolved through the referenced provenance object.

DefinedTermFragment and GlossaryFragment

DefinedTermFragment and GlossaryFragment serve related but distinct purposes.

DefinedTermFragment GlossaryFragment
Represents an individual defined term. Represents a structured glossary or collection of terms.
Establishes the identity and meaning of one term. Establishes the context and organization of multiple terms.
May identify relationships to other terms. May identify the terms belonging to a glossary or vocabulary.
Answers: What does this term mean? Answers: What defined terms belong to this semantic collection?

A DefinedTermFragment may therefore exist independently or participate in a glossary represented by a GlossaryFragment.

DefinedTermFragment and DataFragment

DataFragment DefinedTermFragment
Represents source-observed factual knowledge about an entity or context. Represents the canonical meaning of a term.
Answers: What is known about this object? Answers: What does this term mean?
Example: a plan’s monthly premium is $35. Example: defines what “monthly premium” means within the applicable semantic context.
Publishes factual values. Publishes semantic definitions.

A Machine Fact Object within a DataFragment may reference a defined term when an explicit semantic definition is useful for interpreting the field.

Defined Terms and Machine Fact Objects

Defined terms can provide explicit semantic meaning for fields represented by Machine Fact Objects.

For example, a Machine Fact Object may identify a field as:

avg_moop

while referencing a defined term that establishes the intended meaning:

Average Maximum Out-of-Pocket Limit

The Machine Fact Object publishes the factual assertion. The DefinedTermFragment publishes the meaning of the terminology used to interpret that assertion.

This separation allows factual values and semantic definitions to remain independently maintained while still being explicitly connected.

Read the Machine Fact Objects specification →

Defined Terms and Identity

A defined term is itself an identifiable semantic object.

Its stable term ID allows the same definition to be referenced by multiple fragments, facts, resources, or other knowledge objects without requiring the full definition to be repeated everywhere it is used.

The term’s identity is distinct from the identity of the fragment publishing it.

For example:

  • Fragment ID: identifies the specific DefinedTermFragment.
  • Term ID: identifies the semantic concept represented by that fragment.

This distinction allows term identity to remain stable independently of a particular serialization or publication instance.

Read the Identity specification →

Defined Terms and Resolution

A DefinedTermFragment may participate in machine resolution when a term identifier can be resolved to its canonical definition or related semantic objects.

For example:

Term ID → DefinedTermFragment → Definition → Related Terms

This allows a machine encountering a known term identifier to move toward explicit publisher-defined meaning rather than relying entirely on inferred or general-language interpretation.

DefinedTermFragments therefore support semantic resolution while retaining their original purpose: publishing canonical definitions of identifiable terms.

Read the WebMEM Resolution Model →

Provenance

A DefinedTermFragment should preserve the provenance of the definition it publishes.

Provenance may identify:

  • the person or organization responsible for the definition;
  • the glossary, vocabulary, standard, or source containing the term;
  • the canonical source location;
  • publication or revision dates;
  • version information;
  • license or reuse terms;
  • editorial or usage guidelines;
  • and other lineage information necessary to establish the origin and authority of the definition.

When multiple DefinedTermFragments share the same glossary or vocabulary provenance, the common provenance may be established once and referenced by the individual terms.

Read the Provenance specification →

Conformance

A conforming DefinedTermFragment must:

  • identify itself as a DefinedTermFragment;
  • have an identifiable fragment scope;
  • provide a stable identity for the defined term;
  • provide a human-readable term name;
  • provide an explicit definition;
  • identify semantic scope when the definition depends on a particular domain, glossary, namespace, or vocabulary;
  • identify or reference provenance for the definition;
  • and conform to the applicable WebMEM serialization requirements.

Related terms and other semantic relationships are optional unless required by an applicable domain or conformance profile.

Relationship to WebMEM 1.x

The DefinedTermFragment class originated in the WebMEM 1.x Semantic Data Template specification and remains a defined fragment class in the current WebMEM Protocol.

Earlier specifications serialized DefinedTermFragments using YAML-in-HTML and associated them closely with the Glossary Term Protocol (GTP), glossary federation, semantic digests, and memory-layer behavior.

The current protocol preserves the semantic purpose of the class while separating that purpose from the retired WebMEM 1.x serialization and retrieval mechanisms.

A DefinedTermFragment continues to represent the canonical definition of an identifiable term within a defined semantic context.

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