IPTC Publisher Info - Technical Specification

Version: 0.1.0

Date: 2025-10-15

Status: Draft

1. Introduction

IPTC Publisher Info defines a structured way for media publishers to share comprehensive information about their organisation, policies, and trustworthiness indicators using JSON-LD format embedded within HTML files, following standard schema.org practices.

1.1 Purpose

This standard enables: - Transparency: Clear identification of content publishers - Trust Assessment: Automated evaluation of publisher credibility - Policy Discovery: Easy access to editorial and ethical policies - Interoperability: Standardised format for cross-platform use

1.2 Scope

IPTC Publisher Info covers: - Publisher organisational information - Editorial policies and standards - Trust indicators and certifications - Technical compliance information - Contact and verification details

2. Data Model

2.1 Core Structure

The standard is based on Schema.org's NewsMediaOrganization type with IPTC-specific extensions.

{
  "@context": "https://schema.org",
  "@type": "NewsMediaOrganization",
  // ... core properties
}

2.2 Required Properties

Property	Type	Description	Required
`@context`	string	Schema.org context URL	Yes
`@type`	string	Must be "NewsMediaOrganization"	Yes
`name`	string	Publisher's display name	Yes
`url`	string	Publisher's main website URL	Yes
`description`	string	Brief description of the publisher	Yes

2.3 Recommended Properties

Property	Type	Description	Required
`logo`	string	Publisher's logo URL	No
`legalName`	string	Legal business name	No
`foundingDate`	string	ISO 8601 date format	No
`address`	PostalAddress	Physical address	No
`contactPoint`	ContactPoint	Primary contact information	No
`email`	string	General contact email	No

2.4 Trust Indicators

Property	Type	Description	Required
`hasCertification`	Certification[]	Trust certifications	No
`correctionsPolicy`	string	Corrections policy URL	No
`ethicsPolicy`	string	Ethics policy URL	No
`verificationFactCheckingPolicy`	string	Fact-checking policy URL	No
`diversityPolicy`	string	Diversity policy URL	No

2.5 Technical Compliance

Property	Type	Description	Required
`iptcPubInfo:C2PAcertificate`	string	C2PA certificate URL	No
`masthead`	string	Editorial masthead URL	No

3. Data Types

3.1 PostalAddress

{
  "@type": "PostalAddress",
  "streetAddress": "string",
  "extendedAddress": "string",
  "addressLocality": "string",
  "addressRegion": "string",
  "postalCode": "string",
  "addressCountry": "string"
}

3.2 ContactPoint

{
  "@type": "ContactPoint",
  "email": "string",
  "contactType": "string",
  "telephone": "string"
}

3.3 Certification

{
  "@type": "Certification",
  "certificationIdentification": "string",
  "issuedBy": "Organization",
  "certificationStatus": "string",
  "validFrom": "string",
  "validUntil": "string"
}

4. File Requirements

4.1 File Location

The publisher info file MUST be accessible at:

https://{domain}/.well-known/publisher-info.html

Alternatively, the JSON-LD metadata MAY be embedded directly in existing website pages (such as the homepage or about page) using a <script type="application/ld+json"> tag in the <head> section.

4.2 File Format

Content-Type: text/html; charset=utf-8
Encoding: UTF-8
Format: HTML with embedded JSON-LD
JSON-LD Location: Within <script type="application/ld+json"> tags
Compression: GZIP supported

4.3 File Size

Maximum size: 100KB uncompressed (for standalone HTML files)
Recommended size: Under 50KB
JSON-LD portion: Should be under 25KB for optimal performance

5. Validation Rules

5.1 JSON-LD Compliance

Must be valid JSON within HTML <script type="application/ld+json"> tags
Must include @context and @type
Must use valid Schema.org types
Must be properly escaped within HTML context

5.2 URL Validation

All URLs must be absolute HTTPS URLs
URLs must be accessible (return 200 status)
URLs must point to the same domain or trusted third parties

5.3 Date Format

All dates must use ISO 8601 format (YYYY-MM-DD)
Timezone information is optional

6. Security Considerations

6.1 HTTPS Requirement

Publisher info files must be served over HTTPS
Mixed content is not allowed

6.2 CORS Policy

Files should be accessible for cross-origin requests
Recommended CORS header: Access-Control-Allow-Origin: *
When embedded in existing pages, CORS is handled by the main page

6.3 Content Security

Validate all URLs to prevent SSRF attacks
Sanitize user-generated content
Implement rate limiting for validation endpoints

7. Extensibility

7.1 Custom Properties

Publishers may add custom properties using namespaced prefixes:

{
  "iptcPubInfo:customProperty": "value"
}