HTML <abbr> Tag with the 'title' Attribute

This site is full of <abbr title="HyperText Markup Language">HTML</abbr> codes!

The abbr tag represents an abbreviation or acronym.

It is not mandatory to use the abbr element when presenting an abbreviation or acronym, but it can be useful in some cases (such as using the title attribute to provide an expansion of the abbreviation (as the above example demonstrates).