4.1. Write a valid HTML code following the formal grammar rules of the DOCTYPE used
Use a valid DOCTYPE for each page and make sure the generated HTML code complies with the formal grammar rules of that DOCTYPE (the choice of DOCTYPE is open).
This DOCTYPE must be placed before the
The following aspects of formal grammar are particularly important:
- Elements are nested according to their specifications.
- Elements have complete start and end tags.
- There are no duplicate attributes on an element.
idattribute has a unique value on the page.
Obsolete HTML elements and attributes and/or those intended for formatting purposes only must not be used.