Adobe Experience Manager Forms

I'm looking at the documentation for information regarding prepopulating forms with User data:  http://helpx.adobe.com/aem-forms/6/getting-started.htmlI couldn't find the description of the available options.  I would prefer not to pass a parameter query string with the data.  If a user is authentic...

While creating a dropdown list in my form I noticed a field called "Items Load Path". Can this field be used to provide a url from which it loads the options available in a dropdown list? Where would the URL reside, and how can I put values in that URL? Can someone please show an example?