Picto thématique

Rule n° 71 - The user is warned whenever a field is case-sensitive.

It's annoying to have to re-enter data for an error that is so easy to avoid. But you should also be aware that you should only type in capital letters.

#Accessibility #Forms #Conception #Development


  • Prevent the risk of mistakes and, as a result, prevent the user from having to fill out the same field several times.
  • Prevent confusion in users who think they correctly completed the field, but see it marked as an error.
  • Improve the accessibility of content for people with disabilities.


If the expected entry is case sensitive, specify in the label associated with the field that it must be done in upper or lower case, as appropriate.


For each form

  • Identify the fields whose input is case sensitive by entering the requested text in upper case then in lower case and check whether, in one of the two cases, the input is rejected.
  • If the input is rejected because of its case, check that the label associated with each field, using the label element or in the aria-label attribute, informs the user of the case sensitivity.

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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.

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