I see this often in Adobe SiteCatalyst (Reports and Analytics / Omniture / they've changed the name so many times)
prop6=D=": "+pageName
In the above s_code what does the 'D' do?
(It's difficult to find anything about the above behavior in a standard search)
It's a dynamic variable. Here is some documentation from Adobe:
http://blogs.adobe.com/digitalmarketing/analytics/trimming-the-fat-with-dynamic-variables/