Validation and accessibility of content (accessibility)

ravve published a translation of a good article (thanks to him for that), but in the comments I saw that some habra people believe that the accessibility of the content is ensured only by the successfully completed validation procedure on the W3C website. Far from it . Validation in this case is rather an additional quality criterion for the code that contains the content.

The problem of ensuring the availability of content is wider than just ensuring the validity of the code. Categories of people experiencing difficulties with access to network content are not limited only to the hearing impaired and the visually impaired.

You can provide your site with valid code, but, for example, forget to set a delay for the items in the drop-down JavaScript menu. And lose users who do not have time to click the mouse. And there are lots of similar examples.

Anyone who is interested in the question, I recommend reading the works of Joe Clark - a recognized guru in these matters.