marker-offset
This property specifies the distance between the nearest border edges of a marker box and its associated surrounding box. The value may be specified in any length unit either relative or absolute. Lengths may be negative. So far, this property is not supported by any major browser.
Example
li:before { display: marker; marker-offset: 3em;
content: counter(mycounter, lower-roman) ".";
counter-increment: mycounter;}
Browser and CSS Support Notes
CSS2
No IE support
No Nav or Mozilla support
No Opera support