302.02   Multiple Copies of Documents Should Not Be Filed

37 C.F.R. §2.193(g)(2) 

Parties should not file duplicate copies of correspondence in a single application, registration, or proceeding file, unless the Office requires the filing of duplicate copies. The Office may dispose of duplicate copies of correspondence.

As a general rule, only one copy of each document should be filed, unless more than one copy is specifically required by statute or rule, or a USPTO employee specifically requests more than one copy.

When filing a document electronically or by fax, a party should not send a follow-up copy unless the USPTO specifically requests a follow-up copy.  37 C.F.R. §2.193(g)(2).  Submission of duplicate documents can delay processing.