The HTML5 <dfn> tag is useful when it is necessary for the author to provide a definition of a term. If the certain text has to be stylized, this can be done with the use of CSS. The HTML5 <dfn> tag has to be placed before and after the text that is being defined.
The HTML5 <dfn> tag is readable for all major web browsers like Safari, Google Chrome, Internet Explorer, Opera and Firefox. It is also possible to pair it up with the Event Attributes and global Attributes in HTML5.