AccessiWeb 2.2 - Rule 8.1.2


We check the doctype validity regarding the W3C recommandations (W3C Recommended list of Doctype declarations)

Business description

Criterion : 8.1

Test : 8.1.2

Test description :

For each Web page is the document type (doctype tag) valid?

Level : Bronze

Technical description

Scope : page

Decision level : decidable



The <!doctype> tag of the page


We check the validity of the doctype of the page regarding the "RecommendedDoctypeDeclarations" and "RecommendedCaseInsensitiveDoctypeDeclarations" whitelists

MessageA : Wrong Doctype Declaration
  • code : WrongDoctypeDeclaration
  • status: Failed
  • parameter : none
  • present in source : no


Not Applicable

Selection is empty (The page has no doctype)


The doctype is not found among the doctype whitelist


The doctype is found among the doctype whitelist


HTML5 doctype is NOT case-sensitive:

HTML4: could not find formal statement about case-sensitiveness of doctype:

XHTML1: same as HTML4

From version 2.0, Asqatasun works on the generated html rendered by Firefox. \ We've noticed that for HTML 4.01 doctypes that define the doctype with the "HTML" key in Uppercase, the doctype is transformed and the "HTML" key is changed to lowercase. \ This behaviour is the same with chromium and opera. \ Regarding this fact, we decided to consider all the doctypes as case insensitive despite the W3c recommandations.