Web Content Accessibility Guidelines a guide to the accessibility requirements
4 Robust

4.1.1 Parsing (Obsolete and removed)

Conformance level: A
Criterion released in WCAG version: Removed with WCAG 2.2

Official description of the success criterion

The criterion is now obsolete. Official note from the WCAG recommendation:

This criterion was originally adopted to address problems that assistive technology had directly parsing HTML. Assistive technology no longer has any need to directly parse HTML. Consequently, these problems either no longer exist or are addressed by other criteria. This criterion no longer has utility and is removed.