Sec.  23.37   Station identification.

   (a) General. Every radiotelegraph or radiotelephone station in the
   International Fixed Public or Fixed Public Press Service shall transmit, as
   provided below, the identifying call sign or other approved identification
   signal on each of its assigned frequencies below 30 MHz on which energy is
   being radiated.

   (b) When required. (1) The call sign assigned to each frequency shall be
   transmitted on that frequency at the beginning and end of each period of use
   of the frequency.

   (2) During regular operation on any freuency, the call sign or other
   approved identification signal shall be transmitted at least at hourly
   intervals within the period from 10 minutes before to 10 minutes after each
   hour. If identification during this period would require an interruption in
   the transmission of a radio-photo, a telephone conversation, an addressed
   program or a multiple addressed press message, or a break in the continuity
   of a “conference” or “leased line” type of service, the identifying signal
   shall be transmitted at the first break in, at the conclusion of, or
   simultaneously with, the particular transmission as described below.

   (c) Methods of transmission. (1) All identifying signals shall be
   transmitted in such a manner as to permit identification without special
   equipment other than communication type receivers, except as provided in
   paragraph (e) of this section. When emissions are being used which are not
   capable of identification without special equipment, the identifying signal
   shall be transmitted by one of the following methods:

   (i) By interrupting the transmission and transmitting the call sign in a
   manner which can be identified without special equipment.

   (ii) By superimposing the call sign or other approved identification signal
   on the emission being transmitted without interrupting the transmission as
   provided for by paragraphs (e) and (f) of this section.

   (d) Emissions to be used. (1) Except as otherwise provided, the following
   emissions shall be used for identification:

   (i) Radiotelegraph stations. The identifying call sign shall be transmitted
   by International Morse code at a speed not to exceed 25 words per minute and
   shall consist of the signal “QRA de” followed by the call sign. This
   transmission shall be made at least three times.

   (ii) Radiotelegraph stations using telephone type emissions. When telephone
   type emissions are being used in accordance with  Sec. 23.11, identification may
   be made by voice and shall consist of announcing three times in English the
   call sign of the frequency being used

   (iii) Radiotelephone stations. The identifying transmission may be made
   utilizing either telegraph or telephone type emissions. When telegraph
   emission is used, the transmission shall be made in International Morse Code
   at a speed not to exceed 25 words per minute and shall consist of the signal
   “QRA de” followed by the call sign. This transmission shall be made at least
   three times. When telephone emission is used, the identification shall
   consist of announcing three times in English the call sign of the frequency
   being used, provided that all privacy or secrecy devices shall be removed
   from the circuit during such transmissions.

   (e) Superimposed identification. Radiotelegraph or radiotelephone stations
   identifying simultaneously with transmission of traffic: call signs or the
   general identification signal described in paragraph (f) of this section may
   be superimposed on the emission being transmitted by any method which will
   make identification possible with communication type receivers provided that
   approval of any such method shall first have been obtained from the Federal
   Communications Commission. (Approval by the Federal Communications
   Commission of any means of identification of complex emissions by
   superimposing identification of regular transmissions will be given upon
   satisfactory completion of coordinated tests thereof by the applicant and
   the Commission's Field Engineering Bureau.) Commission approval may be
   withdrawn if at any subsequent time harmful interference to adjacent
   frequencies is caused by the superimposed identification. When superimposed
   identification by call sign is used, the identifying signal shall consist of
   “QTT de (call sign)” transmitted at least three times in International Morse
   Code at a speed not to exceed 25 words per minute.

   (f) General identification signal. When an approved method of superimposed
   identification is used, the identification signal shall consist of “QTT de
   (abbreviated name of company recorded with the Commission) (abbreviated name
   of station recorded with the Commission).” (It is suggested that
   “abbreviated company name” consist of two to five letters such as the
   initials of the company name and that “abbreviated name of station” consist
   of two or three letters indicating the name of the city where the licensee's
   message center is located. Both of these abbreviations shall be notified to
   the Commission before being used for identification.) This general
   identification signal shall be transmitted in International Morse Code at a
   speed not to exceed 25 words per minute and may be transmitted continuously
   or intermittently as desired provided that it shall be transmitted for at
   least five minutes total time during the period from 10 minutes before to 10
   minutes after each hour that energy is being radiated on the frequency. The
   same signal may be superimposed on all transmissions being made at a
   particular station: Provided, however, That licensed call signs shall be
   transmitted on the frequencies to which they are assigned as often as is
   practicable and reasonable or at least at the beginning and end of each
   period of use of each frequency.

   (g) Identification by printer. Notwithstanding the other provisions of this
   section with respect to methods of transmission, when single channel
   start-stop 5 unit code printer equipment is being used, the identifying call
   sign may be transmitted by means of printer signals. When identification is
   made by printer signals, it shall consist of the call sign for the
   particular frequency being used and shall be made at least three times at a
   speed of approximately 60 words per minute.