2.2.9 [CSS-Level2-2009] Section 4.3.5, Counters
The specification states:
Counters are denoted by case-sensitive identifiers (see the 'counter-increment' and 'counter-reset' properties). To refer to the value of a counter, the notation 'counter(<identifier>)' or 'counter(<identifier>, <'list-style-type'>)', with optional white space separating the tokens, is used. The default style is 'decimal'.
Quirks Mode and IE7 Mode (All Versions)
The counters property is not supported.