No parameter.

Displays a window (similar to the window displayed by Help → Show Content Model) showing the content model of implicitly or explicitly selected element. If there is no implicitly or explicitly selected element (for example, if several nodes have been selected), the window shows the content model of the root element.

This command has been added mainly to allow simple XML editors built using XXE components (that is, not XXE itself) to have the same facilities than XXE.