[Horizontal Pane XML tag]

Is there a list of all the properties that can be controlled with XML ?

[Horizontal Pane XML tag]

I am writing another XML file for our report generator. The chart part of the new report will have two panes with a line graph in each one. I can't find the property that places the panes horizontally. We might need to have a tag in the XML that switches the report generator from one to two series with a new pane in each. What XML property specifies that the two panes are horizontal? Is there a list of all the XML properties?