Carat would force it to make an element, unless a node already exists. Tilde indicates the preference for an attribute. "MyXML" is the XML object handle.
Oh... the "?DlgID=Config3" is a query - where you have multiple nodes or elements, you will be able to use this to pick a key attribute or element matched to a specific value. This should be better than blindly using index values (they will still work, too), giving you a bit more freedom, without creating a ton of ActionScript to handle getting the exact location in XML you want.
So.... I'm working on the parser and I may replace the existing parser with this one. It will mean that some features I've never documented will go away, but since you guys never used them, and they were intended to do searches on nodes (easily enough done with indexes, anyway), it won't be a big loss.
As for the edit backgrounds, I'm still considering that idea yet.