Kilotest: Diagnoses of select element invalid violation by HTML element 919 on Mozilla Foundation page

Here is how tools diagnose the select element invalid issue for HTML element 919 of the Mozilla Foundation page.

Basics

Diagnoses

  1. The first child option element of a select element with a required attribute, and without a multiple attribute, and without a size attribute whose value is greater than 1, must have either an empty value attribute, or must have no text content. Consider either adding a placeholder option label, or adding a size attribute with a value equal to the number of option elements.

    Tool: Html Checker API (World Wide Web Consortium)