/ou: /verify /forest: /domain: /ou: Specifies the name of the Active Directory Organizational Unit object that will contain ...

{0} [/ou:] [/verify] [/forest:] /domain:

   /ou: – Specifies the name of the Active Directory Organizational
                Unit object that will contain the Auto-Attendant and 
                Subscriber Access contact objects. 
                Default is '{1}'.
                Specify only the name of OU, not the full DN.
                The search or creation of the OU would happen in the
                current domain.

   /verify –    Prevents all write operations, but verifies the following:
                - Every Exchange UM dial plan created for Enterprise Voice 
                  is assigned a location profile.                   
                - Each Enterprise Voice related UM Auto-Attendant object and
                  Subscriber Access object has a corresponding contact object.
                
   /forest: – Specifies the fully qualified domain name of the Active 
                Directory forest that hosts Exchange Servers 2007, Exchange 
                UM. Required if forest is different.

   /domain: – Specifies the SIP domain name of the SIP URI for which 
                the contact object is created.