47 CFR § 73.3550 - Requests for new or modified call sign assignments.
(a) All requests for new or modified call sign assignments for radio and television broadcast stations shall be made via the FCC's on-line call sign reservation and authorization system accessible through the Internet's World Wide Web by specifying http://www.fcc.gov. Licensees and permittees may utilize this on-line system to determine the availability and licensing status of any call sign; to select an initial call sign for a new station; to change a station's currently assigned call sign; to modify an existing call sign by adding or deleting an “-FM” or “-TV” suffix; to exchange call signs with another licensee or permittee in the same service; or to reserve a different call sign for a station being transferred or assigned.
(b) No request for an initial call sign assignment will be accepted from a permittee for a new radio or full-service television station until the FCC has granted a construction permit. Each such permittee shall request the assignment of its station's initial call sign expeditiously following the grant of its construction permit. All initial construction permits for low power TV stations will be issued with a five-character low power TV call sign, in accordance with § 74.783(d) of this chapter.
(c) Following the filing of a transfer or assignment application, the proposed assignee/transferee may request a new call sign for the station whose license or construction permit is being transferred or assigned. No change in call sign assignment will be effective until such transfer or assignment application is granted by the FCC and notification of consummation of the transaction is received by the FCC.
(d) Where an application is granted by the FCC for transfer or assignment of the construction permit or license of a station whose existing call sign conforms to that of a commonly-owned station not part of the transaction, the new licensee of the transferred or assigned station shall expeditiously request a different call sign, unless consent to retain the conforming call sign has been obtained from the primary holder and from the licensee of any other station that may be using such conforming call sign.
(e) Call signs beginning with the letter “K” will not be assigned to stations located east of the Mississippi River, nor will call signs beginning with the letter “W” be assigned to stations located west of the Mississippi River.
(f) Only four-letter call signs (plus an LP, FM, TV or CA suffix, if used) will be assigned. The four letter call sign for LPFM stations will be followed by the suffix “-LP.” However, subject to the other provisions of this section, a call sign of a station may be conformed to a commonly owned station holding a three-letter call assignment (plus FM, TV, CA or LP suffixes, if used).
(g) Subject to the foregoing limitations, applicants may request call signs of their choice if the combination is available. Objections to the assignment of requested call signs will not be entertained at the FCC. However, this does not hamper any party from asserting such rights as it may have under private law in some other forum. Should it be determined by an appropriate forum that a station should not utilize a particular call sign, the initial assignment of a call sign will not serve as a bar to the making of a different assignment.
(h) Stations in different broadcast services (or operating jointly in the 535–1605 kHz band and in the 1605–1705 kHz band) which are under common control may request that their call signs be conformed by the assignment of the same basic call sign if that call sign is not being used by a non-commonly owned station. For the purposes of this paragraph, 50% or greater common ownership shall constitute a prima facie showing of common control.
(j) A change in call sign assignment will be made effective on the date specified in the postcard acknowledging the assignment of the requested new call sign and authorizing the change. Unless the requested change in call sign assignment is subject to a pending transfer or assignment application, the requester is required to include in its on-line call sign request a specific effective date to take place within 45 days of the submission of its electronic call sign request. Postponement of the effective date will be granted only in response to a timely request and for only the most compelling reasons.
(k) Four-letter combinations commencing with “W” or “K” which are assigned as call signs to ships or to other radio services are not available for assignment to broadcast stations, with or without the “-FM” or “-TV” suffix.
(l) Users of nonlicensed, low-power devices operating under part 15 of this chapter may use whatever identification is currently desired, so long as propriety is observed and no confusion results with a station for which the FCC issues a license.
(m) Where a requested call sign, without the “-FM,' “-TV,” “-CA” or “LP” suffix, would conform to the call sign of any other non-commonly owned station(s) operating in a different service, an applicant utilizing the on-line reservation and authorization system will be required to certify that consent to use the secondary call sign has been obtained from the holder of the primary call sign.