Site Domain 

The site domain specifies the primary domain of the web site you want to track. For example, your site could have the primary domain as well as the subdomains and You should specify the domain without the www prefix.

By default, Webtrends tracks each visitor's traffic across all subdomains. For example, your Webtrends data will show a customer's visit to and as the same visit. If you want to track visits to, and as completely separate visits, then you need to pass the fpcdom config parameter when calling dcs.init().

JavaScript Example:
window.webtrendsAsyncInit = function () {
	var dcs = new Webtrends.dcs();
	dcs.init( {
		dcsid: "dcs9x99xxxx9xxx9xx9xxxx9x_9x9x",
		fpcdom: ""