Overview
"Tag soup" is a term used to denigrate various practices in web authoring. Some of these (roughly ordered from most severe to least severe) include:
- Malformed markup where tags are improperly nested or incorrectly closed. For example, the following:
This is a malformed fragment of HTML.
- Invalid structure where elements are improperly nested according to the DTD for the document. Examples of this include nesting a "ul" element directly inside another "ul" element for any of the HTML 4.01 or XHTML DTDs.
- Use of proprietary or undefined elements and attributes instead of those defined in W3C recommendations.
Read more about this topic: Tag Soup