Source: https://bitlaw.com/source/mpep/2224.html
Timestamp: 2019-04-24 04:22:06+00:00

Document:
Mail Stop "Ex Parte Reexam"
Hand-carried correspondence and correspondence submitted by delivery service should also be marked "Mail Stop Ex Parte Reexam." Whether the correspondence is mailed via the U.S. Postal Service mail or is hand-carried to the Office, it is strongly recommended that the Mail Stop information be placed in a prominent position on the first page of each paper being filed utilizing a sufficiently large font size that will direct attention to it.
Effective July 9, 2007, the U.S. Patent and Trademark Office began accepting requests for reexamination, and "follow-on" papers (i.e., subsequent correspondence in reexamination proceedings) submitted via the Office’s Web-based electronic filing system (EFS-Web). The Office has updated the Legal Framework for EFS-Web to set forth that requests for reexamination, and proper reexamination "follow-on" papers (see MPEP § 2267) are permitted to be submitted using EFS-Web. The current version of the Legal Framework for EFS-Web is at: www.uspto.gov/ebc/portal/ efs/legal.htm.
After the filing of the request for ex parte reexamination, any letters sent to the U.S. Patent and Trademark Office relating to the resulting ex parte reexamination proceeding should identify the proceeding by the number of the patent undergoing reexamination, the reexamination request control number assigned, the art unit, and the name of the examiner.
The certificate of mailing and transmission procedures (37 CFR 1.8 ) may be used to file any paper in an ex parte reexamination proceeding, except for a request for reexamination and a corrected/replacement request for reexamination. This includes the filing of a patent owner’s statement under 37 CFR 1.530, and a requester’s reply under 37 CFR 1.535. See MPEP § 512 as to the use of the certificate of mailing and transmission procedures. The Priority Mail Express® mailing procedure (37 CFR 1.10 ) may be used to file any paper in an ex parte reexamination proceeding. See MPEP § 513 as to the use of the Priority Mail Express® mailing procedure. Again, the filing of a patent owner’s statement under 37 CFR 1.530, and a requester’s reply under 37 CFR 1.535, are included.
Communications from the U.S. Patent and Trademark Office to the patent owner will be directed to the correspondence address for the patent being reexamined. See 37 CFR 1.33(c).
Amendments and other papers filed on behalf of patent owners must be signed by the patent owners, or the registered attorney or agent of record in the patent file, or any registered attorney or agent acting in a representative capacity under 37 CFR 1.34(a). See MPEP § 2213.
Double correspondence with the patent owners and the attorney or agent normally will not be undertaken by the Office.
Where no correspondence address is otherwise specified, correspondence will be with the most recent attorney or agent made of record by the patent owner.
Note MPEP § 2220 on certificate of service.
See MPEP § 2624 for correspondence in inter partes reexamination proceedings.

References: § 2267
 § 512
 § 513
 § 2213
 § 2220
 § 2624