Picto thématique

Rule n° 78 - If any data entered in the form are rejected, the reason(s) why are indicated to the user.

What may seem obvious to the author of a form may be much less so for its users: help them whenever possible.

#Accessibility #Forms #Conception #Development


  • Help users understand what is expected and, by doing so, facilitate their progression to the next step.
  • Prevent user frustration in the face of mistakes for which they don’t have an immediate solution.
  • Improve the accessibility of content for people with disabilities.


For each field containing rejected data, indicate the nature of the error and provide correction help

  • Either at the start of the form, in a list of incorrect fields;
  • Or in the context of each field, as much as possible using itslabel label.


For each form checked:

  • Check for the various possible errors in each form - no input in a field, non-compliance with a requested or predictable format (format of email address, date, etc.), case sensitivity, etc.
  • If the input is rejected, check that the nature of the error is specified to help in its correction, by one of the means indicated in the implementation paragraph.

By Opquast - Read the license

Overview and background

The 240 Opquast rules are defined and agreed upon by an extensive community of web professionals and academics. These web quality assurance guidance rules started as a list of best practices 20 years ago. They have since been revised every five years and have been tried and tested via millions of web interactions by Opquast community’s customers, including the leading CMS communities which have developed plugins for WordPress, Drupal and Prestashop. The most recent version, v4, was established in 2020.

Each rule has individual technical sheets and the rules can be searched by project phase or various topics: e-commerce, data-privacy, internationalization, security, code, etc, or by themes: accessibility, SEO, mobile, privacy, and ecodesign. The complete checklist is available on a creative commons license BY-SA.

To learn more about the Opquast approach, read this article published at Smashing Magazine

Broad application and benefits

The rules should be applied to your projects from the design phase through to post-implementation , and they should be understood by all professionals with web and customer experience (CX) responsibilities: from strategy to operations, marketers to project managers, and editorial to technical staff. The benefits of using this ruleset are numerous, including improving customer satisfaction, web performance, and e-commerce, and expanding your client base, while also decreasing your errors and costs.

Multidisciplinary verticles - accessiiblity, SEO, e-commerce, ecodesign etc..- starting from the foundational Opquast base.

Discover Opquast training and certification

The objective of these rules and the Opquast community mission is ‘making the web better’ for your customers and for everyone! Opquast rules cover the key major areas of risk that can negatively affect website users such as privacy, ecodesign, accessibility and security.

Opquast training has already allowed over 17,000 web professionals to have their skills certified. Train your teams, contact us

We offer a 1 hour free discovery module.