Validation
"All documents must have a W3C recommended Doctype and all Markup must validate against that Doctype."
Rationale
While assistive technologies such as screen readers generally do a good job of interpreting invalid HTML there will be less risk of problems arising if the document follows a recognised standard Doctype.
Techniques
Pass:
<!DOCTYPE html>
<html lang="en-GB">Fail:
<html lang="en-GB">Tests
| Procedure | Expected Result | Type |
|---|---|---|
| Validate the page against the W3C Markup Validation Service | There must be no errors | Tool |