> ## Documentation Index
> Fetch the complete documentation index at: https://wiki.platelunchcollective.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Wikidata QID

> A Wikidata QID is the unique identifier assigned to each entity in the Wikidata knowledge base — a string beginning with 'Q' followed by a number (e.

*Technical implementation* · *Entity & Knowledge Graph*

## Definition

A Wikidata QID is the unique identifier assigned to each entity in the Wikidata knowledge base — a string beginning with "Q" followed by a number (e.g., Q42 for Douglas Adams). QIDs are stable, persistent, and used to link entity data across systems including Wikipedia, Google's Knowledge Graph, and schema.org sameAs arrays.

## Why It Matters for AI Search

A Wikidata QID is the most direct form of entity ID available to most brands. Including a brand's Wikidata QID in its schema.org sameAs array creates an explicit, machine-readable link between the brand's website and its structured knowledge graph record. This link is one of the clearest signals an AI system can receive that two representations of an entity refer to the same real-world organization.

## Related Terms

<CardGroup cols={2}>
  <Card title="Wikidata" href="/ai-search-glossary/wikidata" />

  <Card title="sameAs array" href="/ai-search-glossary/sameas-array" />

  <Card title="Entity ID" href="/ai-search-glossary/entity-id" />

  <Card title="Knowledge graph" href="/ai-search-glossary/knowledge-graph" />

  <Card title="Entity verification" href="/ai-search-glossary/entity-verification" />
</CardGroup>

## Relevant Plate Lunch Collective Services

[Entity SEO](https://www.platelunchcollective.com/services/entity-seo)