+ 2.0 3.0 3.2 4.0 1.0 2.0 3.0 4.0   1.0 2.0 3.0 4.0   1.0 2.0       1.0 2.1       0.9

<acronym> container CSS: in-line element start tag required end tag required Sandia Reference

"The <ACRONYM> element is used to markup abbreviations." (w3)

Example:
HTML

The documentation is quite sketchy on this. The presumption is that should you run the cursor over the acronym the expanded abbreviation should appear as a tool-tip. Nice idea if someone supports it.

class= + 2.0 3.0 3.2 4.0
dir= + 2.0 3.0 3.2 4.0
	"ltr"
	"rtl"
id= + 2.0 3.0 3.2 4.0
index= + 2.0 3.0 3.2 4.0
lang= + 2.0 3.0 3.2 4.0		list of language codes list of country codes
style= + 2.0 3.0 3.2 4.0
title= + 2.0 3.0 3.2 4.0