such registration. (2) Annual notice by the Commission seeking registrations Not later than 120 days after the date of enactment of this Act, and annually thereafter, the Commission shall issue a notice to the public seeking the registration described in paragraph (1). (e) List of voice service providers The Commission may publish a list of voice service providers from which other voice service providers may refuse to accept calls, based on information obtained from the consortium about voice service providers that refuse to participate in private-led efforts to trace back the origin of suspected unlawful robocalls, and other information the Commission may collect about service providers that are found to originate or transmit substantial amounts of illegal calls. (f) Definitions In this section: (1) Commission The term Commission means the Federal Communications Commission. (2) Private-led effort to trace back The term private-led effort to trace back means an effort made by the registered consortium of voice service providers to establish a methodology for determining the origin of a suspected unlawful robocall. (3) Registered consortium The term registered consortium means the consortium registered under subsection (d). (4) Suspected unlawful robocall The term suspected unlawful robocall means a call that the Commission or a voice service provider reasonably believes was made in violation of subsection (b) or (e) of section 227 of the Communications Act of 1934 ( 47 U.S.C. 227 ). (5) Voice service The term voice service — (A) means any service that is interconnected with the public switched telephone network and that furnishes voice communications to an end user using resources from the North American Numbering Plan or any successor to the North American Numbering Plan adopted by the Commission under section 251(e)(1) of the Communications Act of 1934 ( 47 U.S.C. 251(e)(1) )