The optional Account Number field acted more as a memo or record keeping field for the client but has been removed since it is not used during the DRS transfer.
The shares are always sent with the name as displayed on the Outgoing DRS screen and the mailing address on file. If you have an existing account at the Transfer Agent with the same exact information, then they should apply it to that account. However, it is up to the Transfer Agent's discretion as to how they will apply the shares upon arrival. If you do not have an existing account or an account with mismatched information, then the Transfer Agent will open a new account. Any merging between accounts at the Transfer Agent will need to be handled there.
Please contact the Transfer Agent once the shares have been delivered to follow up on their acceptance and handling.