Command line parameters include: /answer[:filename /unattend[:filename /adv /CreateDCAccount /UseExistingAccount:Attach /answer ...

Command line parameters include:

   /answer[:filename]

   /unattend[:filename]

   /adv

   /CreateDCAccount

   /UseExistingAccount:Attach

/answer is used to supply an answer file.
/unattend is used to specify the unattended operation mode
/adv enables advanced user options.
/? will display this help
/CreateDCAccount creates an RODC account
/UseExistingAccount:Attach attaches the server to a DC account

/CreateDCAccount and /UseExistingAccount:Attach are mutually exclusive.
Unattended operation parameters can also be specified on the
command-line.  For example:

   dcpromo.exe /ReplicaOrNewDomain:Replica