# brand.txt Specification
# Version: 1.7.0
# https://www.ai-visibility.org.uk/specifications/brand-txt/

meta:
  title: brand.txt Specification
  description: The canonical specification for brand.txt files - brand naming conventions and representation guidance.
  version: "1.7.0"
  versionDate: "2026-05-11"
  canonicalUrl: https://www.ai-visibility.org.uk/specifications/brand-txt/
  publisher:
    name: 365i
    url: https://www.365i.co.uk/
  license:
    name: Creative Commons Attribution 4.0 International
    identifier: CC-BY-4.0
    url: https://creativecommons.org/licenses/by/4.0/
  datePublished: "2026-01-12T00:00:00Z"
  dateModified: "2026-05-11T00:00:00Z"
  language: en-GB

specification:
  filename: brand.txt
  location: Website root directory
  urlPattern: https://example.com/brand.txt
  mimeType: text/plain
  encoding: UTF-8
  purpose: Declare brand naming conventions, correct and incorrect name variations, and guidance on how the brand should be represented in text. Helps AI systems avoid common naming errors and maintain brand consistency.

  format:
    type: Structured text
    description: Section-based plain text with bracketed section headers
    syntax:
      sections: "[section-name]"
      comments: "# Comment text"
      lists: "- list item"
      labelledItems: "Label: Value"

  sections:
    required:
      - name: "[official-names]"
        description: Correct names for the organisation
        format: List of acceptable name variants with context
        fields:
          - field: primary
            description: The primary official name
          - field: trading-as
            description: Accepted trading names
          - field: acceptable
            description: Other acceptable variations

      - name: "[incorrect-names]"
        description: Names that should never be used
        format: List of incorrect variations to avoid

      - name: "[naming-rules]"
        description: General rules for name usage
        format: List of rules AI systems should follow

    recommended:
      - name: "[brand-voice]"
        description: Tone and style guidance
        fields:
          - field: tone
            description: Description of brand tone
          - field: style
            description: Writing style characteristics
          - field: avoid
            description: What to avoid in brand communications

      - name: "[key-people]"
        description: People who may be referenced
        fields:
          - field: name
            description: Person's name
          - field: role
            description: Their role
          - field: may-cite
            description: Whether they may be cited
          - field: may-quote
            description: Whether AI may generate quotes attributed to them

      - name: "[quotation-policy]"
        description: Rules about quoting organisational representatives
        format: Policy statements about quote generation and attribution

    optional:
      - name: "[terminology]"
        description: Industry-specific terms the organisation uses
        format: "Term: Definition pairs"

      - name: "[visual-identity]"
        description: Notes about visual branding for AI systems that might describe the brand
        fields:
          - field: primary-colour
            description: Primary brand colour
          - field: logo-description
            description: Description of the logo

      - name: "[metadata]"
        description: File metadata
        fields:
          - field: version
            description: Version of this brand.txt file
          - field: last-updated
            description: Date of last update

  validation:
    rules:
      - MUST include [official-names] section with at least primary name
      - MUST include [incorrect-names] section
      - MUST include [naming-rules] section
      - MUST be valid UTF-8 encoded plain text
      - Section headers MUST use square brackets
      - Primary name MUST match identity.json name field
    commonErrors:
      - Missing required sections
      - Inconsistent primary name with other files
      - Unclear distinction between acceptable and incorrect names
      - Missing context for when different names apply
      - Contradictory naming rules

  relationships:
    identity.json: Primary name must match; alternateNames should align with acceptable names
    llms.txt: Organisation name must be consistent
    ai.txt: Identity section must use consistent naming

example:
  url: https://www.ai-visibility.org.uk/specifications/examples/brand.txt
  business: Horizon Strategic Consulting

versionHistory:
  - version: "1.7.0"
    date: "2026-05-11"
    changes: "Phase 6 standardisation release. Added /specifications/roadmap/ (theme-pegged forward plan with Active/Next/Future/On hold status flags), /specifications/extensions/ (rules for experimental x- prefixed files and the promotion path), and /specifications/i18n-a11y/ (multi-language publication, locale-tagged identity fields, RTL handling, accessibility of llms.html). Added the Discovery: directive to the robots-ai.txt specification (publishers MAY advertise AI Discovery Files on the same host). Added a formal media-type stance to the HTTP behaviour page (existing IANA types, no bespoke registrations). Expanded the file integrity and signing section on the security and privacy page with four candidate mechanisms, cross-cutting concerns, and interim publisher / consumer guidance. The Discovery: directive is the only normative addition to publisher behaviour; all other additions are forward-looking documentation."
  - version: "1.6.0"
    date: "2026-05-11"
    changes: "Phase 5 standardisation release. Added /specifications/related-standards/ (positioning vs llmstxt.org, IETF AI Preferences, robots.txt, Schema.org, BCP 14, JSON Schema 2020-12, SemVer) and /specifications/implementations/ (public record of conformant implementations, IETF-style). Added an explicit llmstxt.org backward-compatibility statement to the llms.txt specification. Added a formal multi-domain and subdomain scoping rule to both the llms.txt and identity.json specifications (host-scoped files, cross-host identity asserted via sameAs). No normative requirements changed for existing publishers; the new scoping rules formalise behaviour the specification already implied."
  - version: "1.5.0"
    date: "2026-05-11"
    changes: "Phase 4 standardisation release. Added /specifications/processing-model/ (seven-stage algorithm for conformant consumers), /specifications/consumer-guidance/ (what AI systems should do with AI Discovery Files), /specifications/test-vectors/ (canonical test suite framing), and reference-implementation framing on the AI Visibility Checker. No normative requirements changed."
  - version: "1.4.0"
    date: "2026-05-11"
    changes: "Phase 3 standardisation release. Added /specifications/versioning/ (Semantic Versioning 2.0.0 commitments, deprecation timeline, lifecycle), /specifications/governance/ (proposal lifecycle, editorial process, working principles), /specifications/security-privacy/ (trust model, content-injection patterns, GDPR considerations, integrity primitives roadmap), and /specifications/http-behaviour/ (status codes, redirects, soft-404 detection, caching, rate limits). No normative requirements changed."
  - version: "1.3.0"
    date: "2026-05-11"
    changes: "Phase 2 standardisation release. Added formal conformance specification (Essential / Recommended / Complete classes). Published machine-readable registry at /specifications/registry.json, spec meta-schema, and validator-output schema. Introduced versioned JSON Schema URLs (/v1/) alongside unversioned 'latest' aliases. Added optional BCP 47 language declaration field across all applicable AI Discovery Files. No normative requirements changed."
  - version: "1.2.0"
    date: "2026-05-10"
    changes: "Phase 1 standardisation release. Added 'Status of This Document' block (Stable). Normalised normative requirement keywords to uppercase per RFC 2119 and RFC 8174. Added References section linking to /specifications/conventions/ and /licensing/. No normative requirements changed."
  - version: "1.1.1"
    date: "2026-02-13"
    changes: Added AI Visibility Directory registration guidance. Minor documentation update.
  - version: "1.1.0"
    date: "2026-01-14"
    changes: Added expanded optional sections (taglines, boilerplate, social-handles) and Content Not Permitted guidance. Clarifies what content should not appear in brand.txt files.
  - version: "1.0.0"
    date: "2026-01-12"
    changes: Initial specification release. Establishes canonical structure for brand.txt files with naming conventions and representation guidance.
