We are used to annotate link pseudo classes linke this:
a:link { color: red } /* unvisited links */
a:visited { color: blue } /* visited links */
a:hover { color: yellow } /* user hovers */
a:active { color: lime } /* active links */
Source: http://www.w3.org/TR/CSS2/selector.html#dynamic-pseudo-classes
I assume this order is still correct for CSS3?
Note: Some propose more precise selectors but that is a different topic:
:link:focus, :visited:focus { ... }
:link { ... }
:visited { ... }
:link:hover, :visited:hover { ... }
:link:active, :visited:active { ... }
Source: http://www.thestyleworks.de/tut-art/pc_dynamic_a_name.shtml