611.03(c) Powers of Attorney and Revocations of Powers of Attorney 
Powers of attorney and revocations of powers of attorney must be signed by the individual applicant or registrant or someone with legal authority to bind a juristic applicant or registrant. In the case of joint applicants or registrants, all must sign. 37 C.F.R. §§2.17(c)(2), 2.19(a)(1), 2.193(e)(3).
Associate powers of attorney. Once the applicant or registrant has designated a qualified U.S. attorney, the named attorney may sign an associate power of attorney appointing another qualified U.S. attorney as an additional person(s) authorized to prosecute the application or registration. 37 C.F.R. §2.17(c)(2); see TMEP §§605.01, 605.03, 606.