HTML Attribute Validation

TypeMetal validates certain attribute values, to verify whether they conform to the relevant HTML spec.

When an attribute’s value is valid, you’ll see a green light next to the attribute value.

When TypeMetal detects a problem, it puts a yellow or red light next to the attribute value. You can click the yellow or red light to show a brief explanation of the problem, that’s designed to help you fix it.

The HTML standard specification for the HTML document type you’re working with (e.g. HTML 5, or XHTML 1.0 Transitional) is the ultimate authority regarding valid attribute values. See “HTML” for links to the relevant standard specifications.