The identity of the Database Availability Group (aka DAG) for which to generate the report. The value can be any object that ...

The identity of the Database Availability Group (aka DAG) for which to generate the report.  The value can be any object that can be passed to Get-DatabaseAvailabilityGroup; for example the name of the DAG, a DAG object, the DAG's Guid.  Wildcard strings are acceptable, the script will report on each matching DAG.