For: Design, Development
Parsing (4.1.1 level A)
Validate all page HTML and avoid significant validation / parsing errors. Automated testing alongside some manual testing can be used for this.
Check for the following:
- Use unique ids on a given page, for example make sure the same id does not appear more than once on a page.
- Nest elements according to their specification. For example, test there is no div tag inside a span or li tag inside a div without having ul or ol tags.
- Avoid duplicate attributes, for example providing alt text twice for the img tag
- Make sure that HTML has both start and end tags.
- Make sure no outdated (obsolete) HTML tags are used.