ISO 24495-1 – The ISO Standard for Plain Language
ISO 24495-1 is the first international ISO standard for Plain Language. Published in 2023 by the International Organization for Standardization (ISO), this standard fills a gap that has existed for decades in international normalization. For the first time, a globally valid ISO standard exists that defines the principles of Plain Language and provides concrete guidelines for application in texts and documents.
The full title of the standard is "Plain language – Part 1: Governing principles and guidelines" – making ISO 24495-1 Part 1 of a multi-part series. It defines four governing principles of Plain Language and provides detailed rules, recommendations, and guidelines for creating understandable content. Unlike DIN SPEC 33429, which specifically regulates Easy Language, ISO 24495-1 targets the entire spectrum of clear communication for a broad audience – typically at a B1 level.
The standard is designed to be language-independent: its principles apply equally to English, German, French, or any other language. Language-specific rules are deliberately not defined in the main standard but are left to respective national standards. This makes ISO 24495-1 the first true international reference for clear communication – relevant for governments, businesses, NGOs, and all organizations communicating in writing.
ISO 24495-1 at a Glance
- Publication: June 2023.
- Content: Four governing principles for Plain Language plus guidelines for practical application in documents.
- Language Level: Approximately B1 – clear communication for a general audience.
- Languages: Language-independent – principles apply universally; specific rules are left to national standards.
- Status: Part 1 of an ISO series – further parts for specific fields of application are in development.
The Four Governing Principles of Plain Language
At the heart of ISO 24495-1 are four principles that sum up the essence of Plain Language. According to the ISO standard, a text is considered Plain Language if the audience can achieve four things upon first reading:
- Relevance – Identify relevant content: The audience immediately recognizes if the content is relevant to them.
- Findability – Find content: People can easily find the information they are looking for within the document.
- Understandability – Understand content: The audience understands the content the first time they read it. Word choice and sentence structure must enable clear communication.
- Usability – Use content: The audience can use the information to do what they need to do. Usability is the final and decisive principle.
These four principles – Relevance, Findability, Understandability, and Usability – may sound simple. However, their consistent implementation transforms an organization's entire writing culture. ISO 24495-1 requires authors to write from the audience's perspective rather than their own.
Specific Guidelines and Rules
ISO 24495-1 doesn't stop at abstract principles. It provides detailed guidelines and recommendations across five areas that form the Plain Language toolkit:
- Audience Analysis: Before writing, it must be clear who will read the text and for what purpose. Tone and depth of detail are based on this defined audience.
- Word Choice Rules: The standard recommends familiar, short, and concrete words. Technical jargon should be avoided or explained.
- Sentence Structure Guidelines: Active verbs instead of passive constructions, short sentences with clear structure, and avoiding nested sentences.
- Text Structure: Logical organization with meaningful headings, short paragraphs, lists, and highlighting to ensure findability.
- Testing and Iteration: Content is tested with real readers. Barriers to understanding are fixed iteratively – Plain Language is a process, not a one-time act.
ISO 24495-1 and Digital Accessibility
Clear communication is a core component of digital Accessibility. To make a website accessible to everyone, you cannot stop at technical aspects like alt-texts; the linguistic accessibility of content is just as crucial. ISO 24495-1 provides the internationally recognized framework for this.
In the context of the European Accessibility Act (EAA), while the standard might not be explicitly named, it serves as methodological evidence for fulfilling requirements. Creating content according to ISO 24495-1 automatically satisfies many WCAG requirements regarding understandability – particularly Success Criteria 3.1.3 (Unusual Words), 3.1.4 (Abbreviations), and 3.1.5 (Reading Level).
SiteCockpit Solution
Automatically check Plain Language on the Web
With easyMonitoring, you can check your website content against WCAG understandability criteria – including language tags, reading level indicators, and text structure quality. While editorial revision according to ISO 24495-1 remains a human task, the technical embedding of content can be automated.
Discover easyMonitoring →Frequently Asked Questions about ISO 24495-1
Where can I obtain ISO 24495-1?
The standard is available through the official ISO store or national standards bodies (like DIN in Germany or ANSI in the US). It is generally not provided for free.
Is there a certification for ISO 24495-1?
Currently, there is no official third-party certification of conformity. However, organizations can document their application of the principles internally or through external audits as part of an accessibility report.
Does a website following ISO 24495-1 automatically comply with accessibility laws?
Not necessarily. The standard regulates linguistic clarity, but laws like the EAA also include technical requirements (WCAG). However, Plain Language is a vital building block for total compliance.
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Does your content meet the requirements of clear communication? With easyMonitoring by SiteCockpit, you can automatically identify where WCAG understandability criteria apply – a key step towards implementing ISO 24495-1.
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