Helper class name	Description
.cf	A badass clearfix hack to clear floating elements without using presentational markup. Just apply this to the parent container and you won't need to use anymore. See http://nicolasgallagher.com/micro-clearfix-hack for more details :)
.hidden	Hides an element. Use this as opposed to inline styles.
.elsewhere	Moves an element off the page, hiding it from the user.
.fl .fr	Floats an element left or right, respectively.
.fno	Cancels the floating position of an element.
.clr	Clearing floated elements.
.relative	Relatively positioning an element
.layered	Absolutely positioning an element: removing it from the flow of the document.
.decorative	Force secondary font
.uppercase	Transform text in uppercase
.lowercase	Transform text in lowercase