Tag soup

Syntactically or structurally incorrect webpage markup code

In web development, "tag soup" is a pejorative for HTML written for a web page that is syntactically or structurally incorrect. Web browsers have historically treated structural or syntax errors in HTML leniently, so there has been little pressure for web developers to follow published standards. Therefore there is a need for all browser implementations to provide mechanisms to cope with the appearance of "tag soup", accepting and correcting for invalid syntax and structure where possible.

This keyword could refer to multiple things. Here are some suggestions: