WAI WCAG
4
duplicate-id - id attribute value must be unique
Impact: minor
Ensures every id attribute value is unique
empty-heading - Headings should not be empty
heading-order - Heading levels should only increase by one
Impact: moderate
Ensures the order of headings is semantically correct
image-alt - Images must have alternate text
Impact: critical
Ensures <img> elements have alternate text or a role of none or presentation