37 C.F.R. § 1.32 : Patents, Trademarks, and Copyrights — UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE — GENERAL — RULES OF PRACTICE IN PATENT CASES — NATIONAL PROCESSING PROVISIONS —PROSECUTION OF APPLICATION AND APPOINTMENT OF ATTORNEY OR AGENT — Power of attorney

(a) Definitions.
(1) Patent practitioner means a registered patent attorney or registered patent agent under §11.6.
(2) Power of attorney means a written document by which a principal authorizes one or more patent practitioners or joint inventors to act on the principal's behalf.
(3) Principal means the applicant (§1.42) for an application for patent and the patent owner for a patent, including a patent in a supplemental examination or reexamination proceeding. The principal executes a power of attorney designating one or more patent practitioners or joint inventors to act on the principal's behalf.
(4) Revocation means the cancellation by the principal of the authority previously given to a patent practitioner or joint inventor to act on the principal's behalf.
(5) Customer Number means a number that may be used to:
(i) Designate the correspondence address of a patent application or patent such that the correspondence address for the patent application, patent or other patent proceeding would be the address associated with the Customer Number;
(ii) Designate the fee address (§1.363) of a patent such that the fee address for the patent would be the address associated with the Customer Number; and
(iii) Submit a list of patent practitioners such that those patent practitioners associated with the Customer Number would have power of attorney.
(6) Patent practitioner of record means a patent practitioner who has been granted a power of attorney in an application, patent, or other proceeding in compliance with paragraph (b) of this section. The phrases practitioner of record and attorney or agent of record also mean a patent practitioner who has been granted a power of attorney in an application, patent, or other proceeding in compliance with paragraph (b) of this section.
(b) A power of attorney must:
(1) Be in writing;
(2) Name one or more representatives in compliance with paragraph (c) of this section;
(3) Give the representative power to act on behalf of the principal; and
(4) Be signed by the applicant for patent (§1.42) or the patent owner. A patent owner who was not the applicant under §1.46 must appoint any power of attorney in compliance with §§3.71 and 3.73 of this chapter.
(c) A power of attorney may only name as representative:
(1) One or more joint inventors (§1.45);
(2) Those registered patent practitioners associated with a Customer Number;
(3) Ten or fewer patent practitioners, stating the name and registration number of each patent practitioner. Except as provided in paragraph (c)(1) or (c)(2) of this section, the Office will not recognize more than ten patent practitioners as being of record in an application or patent. If a power of attorney names more than ten patent practitioners, such power of attorney must be accompanied by a separate paper indicating which ten patent practitioners named in the power of attorney are to be recognized by the Office as being of record in the application or patent to which the power of attorney is directed.
(d) A power of attorney from a prior national application for which benefit is claimed under 35 U.S.C. 120, 121, 365(c), or 386(c) in a continuing application may have effect in the continuing application if a copy of the power of attorney from the prior application is filed in the continuing application unless:
(1) The power of attorney was granted by the inventor; and
(2) The continuing application names an inventor who was not named as an inventor in the prior application.
(e) If the power of attorney was granted by the originally named inventive entity, and an added inventor pursuant to §1.48 does not provide a power of attorney consistent with the power of attorney granted by the originally named inventive entity, the addition of the inventor results in the loss of that power of attorney upon grant of the §1.48 request. This provision does not preclude a practitioner from acting pursuant to §1.34, if applicable.

37 C.F.R. §1.32

69 FR 29877, 5/26/2004, as amended at 70 FR 56127, 9/26/2005; 77 FR 48813, 8/14/2012; 80 FR 17956, 4/2/2015