What are the parameters available for the WUA?

The first parameter forces the immediate initiation of a detection and reporting cycle.

The latter parameter is used to expire the AU cookie. The AU cookie normally expires after 60 minutes, and the only scenario in which this parameter would be needed is if you changed group memberships with client-side targeting on an existing client within 60 minutes after the last detection cycle, and wanted to force an immediate update of group data to the WSUS server. In such a case, the /resetauthorization is used in combination with the /detectnow, and the order of the parameters is specific. The command must be 'wuauclt /resetauthorization /detectnow'.