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HTML Checking for Large Sites

Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.

The main element represents the dominant contents of the document, so it should not be contained within another section.

A document must not have more than one main element that does not have the hidden attribute specified.

A hierarchically correct main element is one whose ancestor elements are limited to html, body, div, form without an accessible name, and autonomous custom elements. Each main element must be a hierarchically correct main element.

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Related W3C validator issues