You could decide if your sidebar lists are with egual CSS id or not.

Syntax

$wgSideBarCSS = false;

You obtain that whole sidebar lists have got egual CSS id: titlelist and boxlist.

$wgSideBarCSS = true;

You obtain that each sidebar list has got different CSS id like titlelistNAMETITLELIST and boxlistNAMETITLELIST.

$wgSideBarCSS = "Navigation Bars Portafolio";

You obtain that all sidebar lists have got CSS id titlelist and boxlist but Navigation, Bars and Portafolio title list have got different CSS id like: titlelistNavigation and boxlistNavigation, titlelistBars and boxlistBars, titlelistPortafolio and boxlistPortafolio.