Code QuestionAnswer or Advice
ZAA   You are not observing proper circuit discipline.
ZAB   Your speed key is improperly adjusted.
ZAC   Advise (callsign of) frequency you are reading.
ZAC *  Cease using speed key.
ZAD   Your operating signal (made at ...) received as ... (1) not understood; (2) not held.
ZAE   I am unable to receive you. Receipt through ...
ZAF Will you patch me through to ... (via you or ...) ? I am about to patch you through to ... (via ...).
ZAG   Break .... (1) Go ahead with new text tape; (2) Go back ... feet; (3) Advance your key tape to reference mark number and repeat last transmission (or transmission ...).
ZAH   Unable to relay message ... in present form. (1) not in prescribed format; (2) format lines ... incorrect; (3) no on-line facility available; (4) call signs not encrypted; (5) text not encrypted. We file. Transmit correctly prepared message to all adressees (or to ...).
ZAI   Run ... (1) caller; (2) test tape; (3) synchronizing tape; (4) traffic tape; (5) marking signals; (6) spacing signals; (7) reversals; (8) teletypewriter space bar signals; (9) Date1 test at ... bd.
ZAJ   I have (or ... has) been unable to break you.
ZAK   Transmission interrupted at ... hrs.
ZAK *  Transmission on ... kHz (or ... MHz) suspended until ... (or was suspended at ...) on account of electrical hazards (or ...).
ZAL   Alter your wavelength.
ZAL *  I am closing down (until ...) due to ...
ZAM   I am unable to obtain reply from teleprinter switchboard ... (for connection to ...). Request you call switchboard (or other intermediate switchboard) for me.
ZAN   We can receive absolutely nothing.
ZAN *  Transmit only messages of and above precedence ...
ZAO   I cannot understand your speech, use radiotelegraph.
ZAP   Acknowledge, please.
ZAP *Shall I Work ... (1) simplex; (2) duplex; (3) diplex; (4) multiplex; (5) single sideband; (6) with automatic error correction system; (7) without automatic error correction system; (8) with time and frequency diversity modem ? Work ... (1) simplex; (2) duplex; (3) diplex; (4) multiplex; (5) single sideband; (6) with automatic error correction system; (7) without automatic error correction system; (8) with time and frequency diversity modem.
ZAQ   The last word (or group) (1) received from you (2) transmitted to you was ...
ZAR   Revert to automatic relay.
ZAR *  This is my ... request (or reply) (1) first; (2) second; (3) third; etc.
ZAS   Rerun all tapes run on ... since ... (1) your present frequency; (2) ... kHz (or MHz); (3) call sign ...; (4) this channel or ... channel.
ZAT   I am preparing traffic (perforating tape) for transmission.
ZAU What is teletype range taken on my signal(s) ? Teletype range taken on your signal(s) is ... to ...
ZAV   Transmit traffic for me (or for ...) by broadcast method until further directed (or until ...).
ZAW Shall I transmit 12 inches of blank tape as short intervals ar ... words per minute ? Transmit 12 inches of blank tape as short intervals ar ... words per minute.
ZAX   You are ... (1) causing interference. Listen before sending; (2) causing interference by inattention to order to wait; (3) sending at the same time as ... (call sign); (4) causing delay by slowness in answering; (5) causing delay by slowness in answering my service or procedure messages; (6) answering out of turn.
ZAY   Transmit traffic to me (or to ...) on ... kHz (or MHz) without waiting for receipts. I (or ...) will confirm receipt for traffic later (on ... kHz (or MHz)).
ZAZ   One or more transmitters, simultaneously keying on this broadcast, are defective but transmission will continue on remaining transmitters. Traffic so transmitted will be repeated when full service is restored.
ZBA What is cause of delay (or of bad transmission) ? Delay (or bad transmission) due to ...
ZBB   Make ... copies of the following msg.
ZBB *  For following message you will require a total of ... copies.
ZBC   You are transmitting a continuous ... (1) mark; (2) space.
ZBD Will you repeat what you (or ...) sent (at ...) ? Following is what I (or ...) sent (at ...).
ZBE   Retransmit message ... to ... (for ...) (1) action; (2) information.
ZBF   Use large message formula for the following telegram.
ZBF *  For following message use large message forms.
ZBG   You are transmitting in UPPER CASE.
ZBH   Make preliminary call before transmitting traffic.
ZBI   Listen for radio telephony.
ZBJ What are the estimated errors per thousand characters in my signals (or those of ...) ? The estimated errors per thousand printed characters in your signals (or those of ...) is ... (1) greater than 13; (2) 7 to 12; (3) 1 to 6; (4) nil.
ZBK Are you receiving my traffic clear ? I am receiving your traffic ... (1) clear (2) garbled.
ZBL   I am unable to receive you while I am transmitting. Do not use break-in procedure.
ZBM   Place ... on watch on this frequency: (1) a qualified speed key operator; (2) a competent operator.
ZBN   Break and go ahead with new slip.
ZBN *  Your ... is reversed: (1) tape; (2) mark and space.
ZBO Of what precedence(s) and for whom is (are) your message(s) ? I have (or ... has) ... (numeral followed by precedence prosign for each pre-precendece) message(s) for you (or for ...).
ZBP   Your ... (1) characters are indistinct; (2) spacing is bad.
ZBQ When and on what frequency was message ... received ? Message ... was received at ... on ... kHz (or MHz).
ZBR   Break circuit, retuning.
ZBR *Shall I send by ... (1) direct (R) method; (2) broadcast (F) method; (3) intercept (I) method; (4) repeat back (G) method ? Send by ... (1) direct (R) method; (2) broadcast (F) method; (3) intercept (I) method; (4) repeat back (G) method.
ZBS   Blurring signals, (1) dots heavy (2) dots light.
ZBS *  Your ... (1) dots are too heavy; (2) dots are too light; (3) dots are varying in bias; (4) dot spacing is bad; (5) dots are missing; (6) dots are blurring.
ZBT How do you count following text group(s) ... ? Text group(s) ... should be counted as ... group(s).
ZBU   Report when you are in radio communication with ...
ZBV   Answer me (or ...) on ... kHz (or MHz).
ZBW Will you shift (or ask ... to shift) to transmit on ... kHz (or MHz) ? I am (or ... is) shifting to transmit on ... kHz (or MHz).
ZBX Will you shift (or ask ... to shift) to receive on ... kHz (or MHz) ? I am (or ... is) shifting to receive on ... kHz (or MHz).
ZBY   Break, pull back your tape one yard.
ZBY *  Pass ... (1) on broadcast ...; (2) on broadcast ... single operator; (3) on broadcast ... two operator period; (4) on broadcast ... general periods only.
ZBZ What is the printing acceptability of my signals (or those of ...) ? The printing acceptability of your signals (or those of ...) is ... (1) unacceptable - totally corrupt; (2) unacceptable - very corrupt; (3) unacceptable - partly corrupt; (4) acceptable - occasionally corrupt; (5) acceptable - no corruption.
ZCA   Circuit affected, make readable signals.
ZCA *  Satellite(s) is/are pre-empted from ....Z to ....Z.
ZCB   Circuit broken, signal unheard.
ZCB *  Change to double-hop working using satellites ...West and ...East now (or at ... hours).
ZCC   Collate code.
ZCC *  Establish ... on access ... channel (A/B) (1) 300 dB emergency patch; (2) phase-reverse-keying.
ZCD   Your collation is different.
ZCD *  Weight your access to ... (sall sign) by ... dB.
ZCE   Access satellite ... now (or at ... hours) with ... (1) spread spectrum modulation (normal allocation); (2) spread spectrum modulator changed to access ...; (3) spread spectrum demodulator changed to access ...; (4) frequency modulation; (5) phase shift keying modulation.
ZCF   Check your center frequency, please.
ZCF *  Remove access ... now (or at ... hours) (1) spread spectrum modulation (1 - 40); (2) frequency modulation; (3) phase-reverse-keying; (4) phase shift keying modulation.
ZCG What is your frequency modulation deviation ? My frequency modulation deviation is ...
ZCH What is your tracking mode ? My tracking mode is ... (1) auto track; (2) manual tracking; (3) hand barring.
ZCI   Circuit interrupted. Running and available.
ZCI *What is your ... ? (1) total output power; (2) quality meter reading; (3) number of accesses; (4) frequency modulation access power. My ... (1) is ... watts; (2) is ... %; (3) is ... accesses; (4) is ... watts.
ZCJ Are you experiencing equipment trouble ? I am experiencing equipment trouble with my ... (1) spread spectrum modulator; (2) frequency division multiplex equipment; (3) line modem; (4) time division multiplex equipment; (5) switching or patching; (6) servo system; (7) transmitter; (8) receiver; (9) parametric amplifier; (10) phase shift keying modulator.
ZCK   Check keying.
ZCK *Shall I loop my ... ? (1) spread spectrum modulator channel (A/B); (2) line modem; (3) time division multiplex equipment; (4) frequency division multiplex equipment. Loop your ... (1) spread spectrum modulator channel ...; (2) line modem; (3) time division multiplex equipment; (4) frequency division multiplex equipment.
ZCL   Transmit call letters intelligibly.
ZCL *Have you checked speed setting of all equipment on ... (channel/circuit) ?I have checked speed setting on ... (channel/circuit).
ZCM May I carry out ... on satellite ... ? (1) spread spectrum modulation back-to-back check; (2) range measurement; (3) power balance. Carry out ... on satellite ... (1) spread spectrum modulation back-to-back check; (2) range measurement; (3) power balance.
ZCN Are you ready to synchronize spread spectrum access ? I am ready to synchronize spread spectrum access ...
ZCO   Your collation omitted.
ZCO *  On your FM/FDM access ... (1) suppress telegraph channel ... (1 - 9); (2) open telegraph channel ... (1 - 9).
ZCP   Conditions poor, increase to maximum.
ZCP *  Change (total) radiated power ... (1) on narrow-band to ... watts; (2) on spread spectrum ... watts. Note: this power excluded that for access D or E.; (3) of access ... (1 - 40, N1 - N5, D or E) to ... watts; (4) of access ... (1 - 40, RAE) to ... (0, 3, 6, 9 dB) below full access at combiner unit.
ZCQ   Change FM/FDM mode to mode ... (A/D) with deviation ... kHz.
ZCR   Using concentrator, make warning signals.
ZCR *  I am about to initiate ... (1) serial; (2) parallel synchronization of accesses ... and ...
ZCS   Cease sending.
ZCS *  Switch your spread spectrum access ... modulator to ... (1) code off; (2) search; (3) sync. 1; (4) sync. 2; (5) traffic; (6) channel A normal On; (7) channel B normal On.
ZCT   Send code twice.
ZCT *  My spread spectrum access demodulator is ... (1) CW tuned; (2) in short-code lock; (3) in long-code lock; (4) in long-code and data-lock on channel A only; (5) in long-code and data-lock on both channels.
ZCU   Set spread spectrum access ... channel ... (A/B) to ... (1) 1300 bd.; (2) 2600 bd.; (3) 600 bd.; (4) 1200 bd.; (5) 2400 bd.; (6) 4800 bd.
ZCW Are you in direct communications with ... ?  
ZCW *  (1) Check your ... and advise; (2) I have lost ...; (3) perform back to back through ...; (4) bypass; (5) I have bypassed; (6) retune demodulator to be used in conjunction with ZCX.
ZCX   (1) Test loop 1; (2) Test loop 2; (3) Test loop 3; (4) Test loop 4; (5) paramp; (6) high power amplifier; (7) demodulator; (8) MUX channel A; (9) MUX channel B; (10) DeMUX channel A; (11) DeMUX channel B; (12) coder; (13) decoder; (14) tracking (including side lobe); (15) 5 MHz standard; (16) synthesizer; (17) power supply; (18) modulator; (19) satellite; (20) crypto equipment; (21) patching DC; (22) patching RF; (23) patching clock.
ZCY   Operate at ... (BPS) ... (1) 75; (2) 84; (3) 150; (4) 168; (5) 300; (6) 336; (7) 600; (8) 672; (9) 1200; (10) 2400; (11) 4800; (12) 9600; to be used in conjunction with ZCZ.
ZCZ   (1) Coded; (2) uncoded; (3) satellite access channel at ... dBW; (4) relinquish satellite access due to sole access ...; (5) relinquish satellite access due to violation of power restrictions; (6) increase power to ... dBW; (7) decrease power to ... dBW; (8) NB ALPHA; (9) NB BRAVO; (10) change satellite access channel to ... dBW; (11) satellite.
ZDA   I have a formal message for you (precedence is ...).
ZDB   Expedite reply(ies) to my ... (1) previous operating signal; (2) request(s) for repetition and correction; (3) service message ...
ZDC   Diagnosing circuit faults, will advise.
ZDC *Does the last message (or message ...) require a signal of execution ? Last message (or message ...) requires a signal of execution.
ZDD   Bring message ... to the circuit.
ZDE   Message ... undelivered
ZDE *  Message ... undelivered, (1) station closed until ....Z; (2) attempting alert station to re-open (for Flash or Immediate precedence only); (3) will continue efforts to effect disposal; (4) advise disposition; (5) will not continue further efforts. Request cancel and file; (6) give more complete address.
ZDF   Frequency is drifting to degree indicated, 1...5.
ZDF *  Message ... was (1) received by (addressee(s) designation) at ....Z; (2) received by (addressee(s) designation) communications center at ....Z; (3) delivered to (addressee(s) designation) by broadcast at ....Z; (4) forwarded to (addressee(s) designation) by commercial means at ....Z; (5) mailed to (addressee(s) designation) at ....Z.
ZDG   Accuracy of following message(s) (or message ...) is doubtful. Correction or confirmation will be forthcoming.
ZDH   Your dots are too heavy (long).
ZDH *  Request corrected copy of message ... be forwarded to ...
ZDI   Place this message (or message ...) on ... (1) MERCAST; (2) MERCAST one operator period.
ZDJ How many groups does your message contain ? I have a msg containing ... groups to transmit to you (or to ...).
ZDK Will you repeat message ... (or portion ...) ? Following repetition (of ...) is made in accordance with your request.
ZDL   Your dots are too light (short).
ZDL *  Confirmation ... (1) was omitted (2) differs from text.
ZDM   Your dots missing.
ZDM *  I am holding your message ...
ZDN   Report disposal of message ... your station with any reason for delay.
ZDO   I could not send message ... to ...
ZDP   Hold my message ... until correctness is confirmed.
ZDQ   Message ... was relayed to ... by ... at ... (on ... kHz (or MHz)).
ZDR   This is a multiple-address or book message tape containing ... routing indicators in the routing line, which is to be routed in accordance with the established doctrine.
ZDS   Message (or message ...) which you have (or ... has) just forwarded was incorrectly transmitted. Correct version of message (or part or portion ...) is ...
ZDT   Following transmitters running dual.
ZDT *  Exercise messages are not to be sent until further orders (or until ...).
ZDU   Pass the following ... (1) private message (telegram); (2) service telegram; (number of words charged for is ...).
ZDV   Your dots varying length, please remedy.
ZDV   Private message (telegram) received for ..., request instructions.
ZDW   In addition to the regular broadcast times, this hydrographic message is to be transmitted on the following hydrographic schedules ... (1) ... schedule; (2) all schedules on ... (date); (3) all schedules from ... to ... (dates) inclusive.
ZDX   Messages up to and including serial (or circuit) number ... have been previously transmitted.
ZDY   Private messages (telegrams) are not to be sent until further orderes (or until ...).
ZDZ   On ... (date) message(s) was (were) mailed to ... (command(s)) bearing serial numbers ...
ZEA   Pass plain language copy to ... by secure means.
ZEB   This is a reprocessed ICAO message.
ZEC Have you received message ... ? Message ... (1) not received; (2) unidentified: give better identifying data.
ZED   Experiencing drop-outs, 1...5.
ZED *  The following confirmatory information as received is at variance with the text.
ZEE   Request message ... be transmitted.
ZEF   We are experiencing fill-ins, 1...5.
ZEF *  This message has been read (received or intercepted) from a ship at sea.
ZEG   We are experiencing garbles, 1...5.
ZEG *  This message is not to be decrypted or reported outside the communications center in ... (1) aggressor force; (2) friendly force.
ZEH   Accuracy or ... portion of following message (or message ...) is doubtful. Correction or confirmation will be forwarded when received. (1) heading (2) text (3) group ... to ...
ZEI   Accuracy is doubtful of heading of message received as follows ... Check to station of origin if necessary and repeat.
ZEJ   Replies to this message (or message ...) are to be sent now (or at ...).
ZEK   No answer is required.
ZEL Is message ... a correction to message ... which was previously transmitted with doubtful or missing groups (words) ? This message is correction to message ... (transmitted by ...). Note - may only be used in conjunction with ZDG.
ZEM   Reserved for Intelligence Community use only.
ZEN   This message has been delivered by a separate transmission or by other means (1) messenger/courier; (2) mail; to the addressee(s) immediately following this operating signal.
ZEO   Transmit this message by rapid means when no charges are involved and to all others by mail.
ZEP   This message (or message ...) was incompletely received. Each word or group missed, which is indicated by position of ZEP in the message, will be forwarded as soon as obtained.
ZEQ   Message ... (or this message) has been ... (1) missent to this station. Received at ....Z. Message protected; (2) missent to this station and unable to protect delivery due to ... Request you re-transmit to the appropriate called station(s); (3) misrouted to this station and has been rerouted to ... at ....Z. Recommend corrective action; (4) Misrouted to this station and unable to protect delivery (for ...) due to ... Request your station protect delivery; (5) Routed to this station in format line 2, but without delivery responsibility in format lines 7 or 8. Advise; (6) Delayed due to misrouting, and is being retransmitted herewith.
ZER   This is a multiple-address or book message tape containing ... routing indicators in the routing line for which the station called in the pilot is responsible.
ZES   Your message ... has been received ... (1) incomplete (2) garbled. Request retransmission.
ZET   Message ... has been protected and no further action by ... is required.
ZEU   Exercise (drill) message.
ZEV Request you acknowledge message ... Message (or message ...) is acknowledged.
ZEW   Your attention is invited for ... (1) action; (2) information; to message ... which is in your files.
ZEX   This is a book message and may be delivered as a single-address message to addressees for whom you are responsible.
ZEY   This message (or message ...) has been (or will be) put on the ... broadcast schedules (serial number ...).
ZEZ   When delivery is effected of this book message to addressee by commercial means, or when copy is forwarded to confirm message previously delivered by telephone, it is to be sent as a single address message. Note - may only be used in conjunction with ZEX.
ZFA   Failing auto.
ZFA *  Following message has been read (received or intercepted).
ZFB   Signals are fading badly.
ZFB *  Pass this message to ... (1) on arrival; (2) on return to base.
ZFC   Check your FSK shift, please.
ZFC *Have you received (or sent) the executive signal ("Execute") for message ... ? Executive signal ("Execute") for last message (or following message) has been made (or was made at ...).
ZFD   Depth of fading is as indicated, 1...5.
ZFD *  This message is a suspected duplicate.
ZFE   Pass message ... (which is in your files) to addressee(s) for whom you are responsible using the indicated supplementary heading.
ZFF   Inform me when this message (or message ...) has been received by ... (addressee designation) or by ... (1) action addressee(s); (2) information addressee(s); (3) all addressees; (4) action addressee's/adressees' message center; (5) information addressee's/addressees' message center; (6) all addressees' message center. (Note: not authorized for use on general messages).
ZFG   This message is an exact duplicate of a message previously transmitted, and is to be delivered to all appropriate addresses served by the receiving communications facility.
ZFH   This message (or message ...) is being (or has been) passed to you (or ...) for ... (1) action; (2) information; (3) comment; (at the request of ...).
ZFI Is there any reply to message ... ? There is no reply to message ...
ZFJ   Message(s) ... number(s) ... not transmitted on this schedule (or on schedule ...) are no longer needed.
ZFK   Revert to FSK.
ZFK *Does message ... (or station serial number ...) concern me (or ...) ? Message ... (or station serial number ...) (1) does not concern you (or ...); (2) no longer concerns you (or ...).
ZFL Was there any traffic addressed to me on ... broadcast schedule between serial numbers ... and ... ? Following traffic was addressed to you on ... broadcast schedule between serial numbers ... and ...
ZFM   Message(s) serial number(s) ... (to ...) which was (were) transmitted during unserviceability of one or more transmitters, simultaneously keyed, will now be repeated.
ZFO   Signals faded/fading out.
ZFO *  Message ... is being delivered as a Basegram message.
ZFP   Basegram.
ZFQ   Frequency shift of your signal is ... Hz.
ZFQ *  Two messages (... and ...) received under channel number (or station serial number) ... Both released.
ZFR   Rapidity of fading is as indicated, 1...5.
ZFR *  Cancel transmission ... (made under channel or station serial number ...).
ZFS   Signals are fading slightly.
ZFS *  Make message ... same channel or station serial number as this procedure message.
ZFT   Message ... received without channel number(s) (or station serial number) following message bearing channel number (or station serial number) ... Message released.
ZFU   Channel numbers ... and ... preceded message ... Lower number was recorded and the higher number blanked.
ZFV   Message ... containing channel number(s) ... separated by portions of the message, released subject to correction. Take necessary action to provide corrected copy (to).
ZFW   BLANK channel number(s) ...; forward message ... as channel number ...
ZFX   Channel number (or station serial number) ... is open.
ZGA What is my call sign for use on this circuit only ? Your callsign for use on this circuit is ...
ZGB   Send (answer) ... (1) in alphabetical sequence of call signs; each station to make its call sign once (or ... times); (2) in the following sequence of call signs.
ZGC   Station to station receipts are not required for this FLASH message (authorization for use must be prescribed by authorities controlling network/systems).
ZGD   Two stations are using the same indefinite callsign on ... kHz (or MHz). Both stations are to select different call signs.
ZGE   Send your call sign(s) once (or ... times) on this frequency (or on ... kHz (or MHz)).
ZGF   ... signals good for ... wpm.
ZGF *  Make callsigns more distinctly.
ZGG What is call sign of ... (1) friendly striking force aircraft; (2) friendly shadowing aircraft; (3) incoming vessel; (4) senior officer present afloat (or Officer in tactical command); (5) ship acting as flagship for ... ? Call sign of ... is ... (1) friendly striking force aircraft; (2) friendly shadowing aircraft; (3) incoming vessel; (4) senior officer present afloat (or Officer in tactical command); (5) ship acting as flagship for ...
ZGH   I am using this transmitter to answer calls on two or more frequencies. Answer to calls may be delayed.
ZGI   I am or have been (or ... is or has been) calling you (on ... kHz (or MHz)).
ZGJ When will you call me again on present frequency (or on ... kHz (or MHz)) ? I will call you again as soon as possible (or at ...) on present frequency (or on ... kHz (or MHz)).
ZGK When shall I call you on present frequency (or on ... kHz (or MHz)) ? Call me again at ... on present frequency (or on ... kHz (or MHz)).
ZGL   ... will answer calls for me (or for ...).
ZGM Did you (or ...) hear ... (at ...) ? I have (or ... has) been unable to communicate with ... (since ...).
ZGN When was I (or ...) last heard ? Nothing was heard from you (or ...) (since ...).
ZGO What is my number and sequence in answering ? Your number is ...; answer after number ... (numbers to be separated by separative signs.
ZGP   Please give priority.
ZGP *  Answer calls for me on present frequency (or on ... kHz (or MHz)).
ZGS   Your signals getting stronger.
ZGW   Your signals getting weaker.
ZHA How are conditions for auto reception ?  
ZHA *Shall I decrease frequency very slightly (or ... kHz) to clear interference ? Decrease frequency very slightly (or ... kHz) to clear interference.
ZHB Shall I increase frequency very slightly (or ... kHz) to clear interference ? Increase frequency very slightly (or ... kHz) to clear interference.
ZHC How are your receiving conditions ?  
ZHM   Harmonic radiation from transmitter ...
ZHN How do you receive my automatic transmission ? Your automatic transmissions are ... (1) good; (2) fair; (3) unreadable.
ZHO What is your speed of automatic transmission in ... (1) revolutions per minute; (2) words per minute; (3) bauds ? My speed of automatic transmission in ... (1) revolutions per minute; (2) words per minute; (3) bauds; is ...
ZHP What is preventing automatic reception ? Automatic reception is prevented by ...
ZHQ   Please listen for me on ... kHz (or MHz) and transmit to me on ... kHz (or MHz).
ZHR Is my speed of automatic transmission correct ? Your speed of automatic transmission is ... (1) fast; (2) slow; (3) erratic; (4) correct.
ZHS   Send high speed auto ... wpm.
ZHY   We are holding your ...
ZIA   This message (or message ...) is being (or has been) passed out of proper sequence of station serial numbers.
ZIB Two messages ... and ... (or group counts and time of origin ... and ...), both received as serial number ...; what are correct serial numbers ? Change station serial number of message ... to read number ... or Assign to message ... station serial number ...
ZIC What is (are) station serial number(s) or channel number(s) of last message(s) you transmitted to me (or to ...) ? Station serial number(s) or channel number(s) of last message(s) transmitted to you (or to ...) is (are) ...
ZID What is (are) station serial number(s) or channel number(s) of last message(s) you received from me (or from ...) ? Station serial number(s) or channel number(s) of last message(s) received from you (or from ...) is (are) ...
ZIE   Station serial number(s) or channel number(s) (from ...) has (have) not been received. Repeat message(s) or cancel serial number(s) or channel number(s).
ZIF   I (or ...) did not use serial number(s).
ZIG Is (are) number(s) ... (to ...) blank ? Number(s) ... (to ...) is (are) blank.
ZIH   Repeat headings of message numbers ... to ... transmitted by you (or ...) to check serial numbers.
ZII What was ... of your (or ...'s) number ... ? (1) date-time group; (2) filing time. My (or ...'s) message number ... had following ... (1) date-time-group; (2) filing time.
ZIJ   I am now changing my channel number/letter. Last number sent in this series is that of this message.
ZIK   This is a weather control message which is not to be transmitted in the clear over radio circuits.
ZIL What channel number(s) should I use ? Use channel number(s) ...
ZIM   Industrial or medical interference, 1...5.
ZIP   Increase power.
ZIP *  Have set continuous watch, or (1) single operator period; (2) two operator period; (3) general periods only; (4) reduced single operator periods; on broadcast indicated. First serial number received is .../No number yet received.
ZIQ   Have ceased watch on broadcast, last number received ...
ZIR   You have strong idle radiation.
ZIS   Atmospheric interference, 1...5.
ZJA   Reading signaling light of ...
ZJB May I close down visual watch now (or at ...) ? Close down visual watch now (or at ...).
ZJC   Repeat all flag signals made by the senior officer (senior officer present afloat).
ZJD   Use ... (1) better light; (2) better background.
ZJE   Set virual watch now (or at ...).
ZJF *  Frequency jumping to degree indicated, 1...5.
ZJF *  Visual relaying station between senior officer (senior officer present afloat) (or ...) and ... is to be ...
ZJG   Repeat all flashing (or semaphore) messages made by the senior officer (senior officer present afloat).
ZJH   Your light is unreadable ... (1) not trained correctly; (2) not bright enough; (3) too bright.
ZJI What are the call signs of the ships in company with you ? Call signs of the ships in company with me are ... (for visual use only).
ZJJ   Use double-flash procedure.
ZJK Are you (or is ...) visual guard for ... ? I am (or ... is) visual guard for ...
ZJL   Hoist the following signal.
ZJM   (1) Flaghoist; (2) semaphore; (3) 20 inch signalling projector; (4) 10 inch signalling projector; (5) ALDIS; (6) intermediate; (7) heather; (8) daylight signalling latern; (9) masthead flashing light; (10) infrared; (11) signal search light; (12) omni-directional flashing light; (13) directional flashing light.
ZJN   Message ... has been passed to those for whom I am responsible (or to ...) (at ...) but "L" has not been received.
ZJO   Repeat back each group of the text of this message as it is transmitted.
ZJP   Message which follows is to be encrypted and passed to all addressees (by ...). (Only to be used by visual not liable to interception).
ZJQ   Repeat signal (or message ...) the senior officer (senior officer present afloat) (or ship indicated) is now transmitting or is about to transmit.
ZJR   Only semaphore is to be used for visual signaling between ... and ... (or from ...).
ZJS   Directional lights of minimum brilliancy are to be used for all visual traffic between ... and ... except for messages of precedence priority and above requiring transmission to two or more ships.
ZJT   Broadcast transmitter indicated is about to be taken off for ... minutes (or until ...).
ZKA Who is controlling station (net control station) on this frequency (or on ... kHz (or MHz)) ? I am (or ... is) controlling station (net control station) on this frequency (or on ... kHz (or MHz)).
ZKB Is it necessary to obtain the permission of the controlling station (net control station) before transmitting messages ? It is necessary to obtain the permission of the controlling station (net control station) before transmitting messages.
ZKC   Substitute code sign (call sign) of control station of group (net) in place of this operating signal.
ZKD Shall I take control of net (for ...) (until ...) ? Take control of net (for ...) (until ...).
ZKE   I (or ...) report(s) into the circuit (net).
ZKF   Station leaves net temporarily (or for ... minutes) (to communicate with ...) (will be on ... kHz (or MHz)).
ZKG   Observe (or direct ... to observe) schedule with ... on ... kHz (or MHz) (at ...).
ZKH Did you (or ...) observe schedule with ... (at ...) ? I (or ...) observed schedule with ... (at ...).
ZKI   Set watch on ... kHz (or MHz) ... (1) continuous; (2) until further notice.
ZKJ May I close down (until ...) ? (1) close down (until ...); (2) I am closing down (until ...).
ZKK   Assume radiotelegraph (wireless) organization ... forthwith (or at ...).
ZKL   Resume normal radio communication now (or at ...).
ZKM   Take guard (for ...) (on ... kHz (or MHz)).
ZKN   I have taken guard on ... kHz (or MHz).
ZKO   Revert to on/off keying.
ZKO *  I have handed over guard (to ...) (on ... kHz (or MHz)) (serial number of last message received was ...).
ZKP Are you (or is ...) radio guard for ... (on ... kHz (or MHz)) ? I am (or ... is) radio guard for ... (on ... kHz (or MHz)).
ZKQ   Say when ready to resume.
ZKQ *  Indicate ships or stations for which you are (or ... is) ... guard. (1) radio (on ... kHz (or MHz)); (2) visual.
ZKR On what frequencies are you (or ...) maintaining watch? I am (or ... is) maintaining watch on ... kHz (or MHz).
ZKS What stations are keeping watch on ... kHz (or MHz) (or are in net) ? Following stations are keeping watch on ... kHz (or MHz) (or are in net).
ZKT   I am keeping watch on ... kHz (or MHz) for ... (1) first five minutes in each half hour; (2) from 10 to 15 and 40 to 45 minutes past the hour; (3) between ... and ... minutes past the hour.
ZKU   I am (or ... is) maintaining continuous watch, or (1) single operator period; (2) two operator period; (3) general periods only; (4) reduced single operator period; on ... (call sign) ... broadcast.
ZKW   Keying weight is ... percent.
ZLA   I have pictures of the following types to transmit ... (1) photographs; (2) weather maps; (3) blueprints; (4) printed matter; (5) test.
ZLB   Give long breaks, please.
ZLB *What drum rotation speed shall I use ? Transmit at ... revolutions per minute. (1) 30; (2) 45; (3) 50; (4) 60; (5) 90; (6) 100.
ZLC   Your transmission ... (1) shows objectionable modulation; (2) suitable for communication but not for picture; (3) shows caption too close to edge of picture; (4) shows buckled print; (5) shows fork drift; (6) picture shows too much contrast; (7) picture shows insufficient contrast; (8) picture shows cross-over.
ZLD   We are getting long dash from you.
ZLD *  I am unable to ... (1) synchronize with you; (2) transmit pictures; (3) copy pictures.
ZLE   Send ... (1) fence; (2) white; (3) black; (4) picture; (5) synchronize; (6) fence swinging black until I stop you; (7) fence swinging white until I stop you.
ZLF   (1) inverter; (2) converter; (3) 96-line 12x18 transceiver; (4) 100-line transceiver; (5) 300-line transceiver.
ZLG Shall I transmit ... (1) negative; (2) positive ? Transmit ... (1) negative; (2) positive.
ZLH Will you transmit map(s) ... (... area ... time ... type) ? I am going to transmit map(s) ... (... area ... time ... type).
ZLI   Reverse material on drum and rerun until I break you.
ZLJ What size lettering shall I use ? Use ... (1) standard telegraphic typewriter; (2) jumbo typewriter if available; (3) hand lettering at least 3/16 of an inch high.
ZLL   Distorted landline control signals.
ZLN   Facility indicated cannot be operated at present.
ZLO Is (are) facility(ies) ... operative at your station (or at ...) ? The following ... facility(ies) is (are) operative at this station (or at ...). (1) homing beacon; (2) radar beacon; (3) revolving and/or flashing beacon; (4) radio beacon; (5) instrument landing system; (6) ground control approach; (7) approach control; (8) tower transmitter (state which type LF, MF, VHF, or UHF); (9) MF direction finder; (10) VHF direction finder; (11) UHF direction finder; (12) runway lights; (13) Sandra lights; (14) radio track guide; (15) radio range.
ZLP   Low (minimum) power.
ZLP *What is (are) the magnetic line(s) of shoot of the ... (facility) ? The magnetic line(s) of shoot of the ... (facility) is (are) ... degrees.
ZLS   We are suffering from lightning storm.
ZMA What was bearing of unknown station (or station using call sign ...) at ... (time) (on ... kHz (or MHz)) ? Bearing of unknown station (or station using call sign ...) was ... (at ... time) class ... (on ... kHz (or MHz)).
ZMB   Bearing of you (or of ...) was ... (class ...) from me (or from ...) at ... (time).
ZMC   Bearing of station which answered message (or transmission) from ... was ... (at ... (time)) class ... (on ... kHz (or MHz)).
ZMD   (1) Your bearing appears to be between ... degrees and ... degrees, and sense indicates you are to the ... (direction) of this station; (2) your bearing is changing rapidly.
ZME   Pass in direction finding bearing (of ...) obtained on ... kHz (or MHz) (or between ... and ... kHz (or MHz)).
ZMF Will you endeavor to obtain a direction finding bearing of station now transmitting (or of ...) (on ... kHz (or MHz)) ? Bearing of station now transmitting (or of ...) (on ... kHz (or MHz)) was ... (class ...) sense determined at ...
ZMG   Magnetic activity.
ZMG *  This bearing (course or position) is unrealiable. Error in excess of class C bearing (or position) may amount ... degrees (or miles).
ZMH   Surface craft using call sign ... cooperating. Change to ... kHz (or MHz) and follow direction finding procedure when called.
ZMI Will you send your call sign and dashes of five-seconds duration at intervals in order that I (or ...) may home on you ? I am about to send my call sign and dashes of five-seconds duration at intervals in order that you (or ...) may home on me.
ZMJ   Check ... (1) correctness of last QDR; (2) sense of last QDR; (3) correctness of last QDM; (4) sense of last QDM.
ZMK   Cannot determine your (or ...'s) ... (1) position; (3) bearing.
ZML   Steer ... degrees for 2 minutes if possible and send call sign and long dashes while you are so doing.
ZMM   Increase height to enable more accurate bearing to be completed.
ZMN   Change over to loop direction finding on ... kHz (or MHz) (and home on transmission made by ...).
ZMO   Stand by moment.
ZMO *What is my position by direction finding bearing from nearest landmark (or from ...) ? Your position by direction finding cross bearings from nearest landmark (or from ...) is ... (class ...) at ... (hours).
ZMP   Mispunch or perforator failures.
ZMP *  Endeavor to plot position from bearings taken on station(s) now transmitting (or of ...) (on ... kHz (or MHz)).
ZMQ   Stand by for ...
ZMQ *  Cannot determine your position, you are in line or nearly in line with direction finding station baseline.
ZMR   Take over direction finding guard as previously ordered (on ... kHz (or MHz)) (from ... to ... kHz (or MHz)).
ZMS   Carry out direction finding procedure (as locally pre-scribed).
ZMT   Sense determination unreliable; bearing may be reciprocal.
ZMU   Multipath making ... mark bias.
ZMU *  (1) Listen (for ...) on direction finding on ... kHz (or MHz) (or between ... and ... kHz (or MHz)); (2) shift to direction finding frequency ... and listen for call sign ...
ZMV What is the grid course for me to steer to reach you (or ...) ? The grid course for you to steer to reach me (or ...) is ... degrees at ... hours.
ZNA   You are encrypting ... incorrectly. (1) operating signals; (2) radio call signs; (3) address groups.
ZNB   No breaks, we send twice.
ZNB *What is authentication of ... (1) message ...; (2) last transmission; (3) ... ? Authentication (of ...) is ... (1) message ... (2) last transmission (3) ...
ZNC   No communications with ...
ZNC *  All transmissions will be authenticated ... (1) on all circuits; (2) on this circuit; (3) on ... frequency.
ZND   Your are using authenticator incorrectly ... (1) verify authenticator system key; (2) check authentication of your last transmission.
ZNE   I am prepared to authenticate.
ZNF   Addresses who are not holders of the cryptographic system employed in the text need not decrypt (decipher), but shall sight (read) translation at first opportunity and obtain copy if applicable.
ZNG   Receiving conditions no good for code.
ZNG *  Commands who are included in the collective address used in this heading, who are not holders of the cryptographic system employed in the text, are exempted.
ZNH   Plain-text tape of this message should be prepared during the process of decipherment.
ZNI   No call letters (identification) heard.
ZNI *  Shift to ... (1) on-line; (2) plain; operation now.
ZNJ   This message has been transmitted under serial number ... at ... by station whose designation follows ... (1) by on-line cipher; (2) by off-line encryption.
ZNK   Addresses who do not hold cryptographic facilities are exempted.
ZNL   Receiving cryprographic office concerned should refer queries to the text of this message (e.g., requests for verification) to ... (address designators except plain language). Note: to be used in codress messages when necessary to indicate originating crypto center and then normally limited to messages of Immediate precedence and above.
ZNM   Originaor authorizes the transfer of this message into the secure networks of all authorities addressed, provided the networks are approved for the security classification of the message involved.
ZNN   All clear of traffic now.
ZNO   Not on the air.
ZNO *  Unable to decrypt message ... (from indefinite call sign ...). Note: only to be used under circumstances laid down in cryptographic instructions.
ZNP   Transfer operation of channel now to ... (1) normal; (2) top secret; (3) conference; (4) engineering; on-line cipher operation. Note: this signal is for use only when already in on-line cypher operation.
ZNQ   This message (or message ...) received at this station ... (1) without authentication (when authentication is in force); (2) incorrectly authenticated; (3) correctly authenticated.
ZNR   Not received.
ZNR *  This message may be forwarded without change by radio or non-approved circuit. Note: the letter U repeated five times following this operating signal indicates that the message which follows is unclassified or is acceptable for transmission over any circuit in its present form.
ZNS   Here new slip.
ZNS *  Following message has been authenticated ... (this signal is for use only over approved(on-line circuits).
ZNT   Following message has NOT been authenticated ... (this signal is for use only over approved(on-line circuits).
ZNX   You have disclosed an EEFI as indicated: (1) position; (2) capabilities; (3) operations; (4) EW; (5) personnel; (6) COMSEC; (7) wrong circuit; (8) (SPARE); (9) (SPARE); (10) (SPARE); Note: see ACP 124 for details of BEADWINDOW procedure and the use of EEFI numbers.
ZNY   Do not forward this message unencrypted by radio or non-approved circuit. Note: a letter repeated five times following this operating signal indicates the classification for which the circuit must be approved before the message can be forwarded over it.
ZNZ   Originator has indicated that this message should be forwarded without service action on the test at relay or addressee stations, as the information conveyed is ... (1) perishable; (2) for information only and will be confirmed by other means.
ZOA   Have checked ... (call letters) OK.
ZOA *  Relay this message (or message ...) by visual (to ...).
ZOB   Take (I will take) no further action regarding forwarding message ...
ZOC   Station(s) called relay this message to addressees for whom you are responsible.
ZOD   Observing ..., will transfer when better.
ZOD *  Act as radio link (relaying station) between me and ... (or between ... and ...).
ZOE Can you accept message for ... ? (1) on line; (2) off line. Give me your message. I will dispose of it ... (1) on line; (2) off line.
ZOF   Relay (pass) this message (or message ...) to ... now (or at ...).
ZOG   Transmit (pass) this message (or message ...) to ... (for ...) (1) action; (2) information.
ZOH What traffic have you on hand ? Traffic on hand.
ZOH *  Send message for ... on ... kHz (or MHz) by ... (1) receipt method; (2) broadcast method; (3) intecept method.
ZOI   Pass this message to the nearest (or ...) weather central/control.
ZOJ   This is corrected version number ... (1) one; (2) two; etc. of a message previously transmitted with errors and/or omitted portions.
ZOK   We are receiving OK.
ZOK *  Relay this message via ...
ZOL   OK, on line.
ZOL *  I will relay your call sign to senior officer present afloat, whose call sign is ...
ZOM   Delivery of this message by mail in lieu of broadcast permissible (to ...).
ZON   Place this message (or message ...) on ... (1) continuous wave broadcast; (2) radioteletype broadcast; indicated by following specific broadcast designator(s) ...
ZOO   Place this message (or message ...) on MERCAST indicated by following specific broadcast designator(s) ...
ZOP   This message (or message ...) has been delivered to all broadcast areas (or to the following specific broadcast area(s) ...).
ZOQ   Deliver this message (or message ...) to all broadcast areas (or to the following specific broadcast area(s) ...).
ZOR   Transmit only reversals.
ZOR *  (1) Route traffic for ... via ... area broadcast. (2) Beginning at ... traffic for you (or ...) will be routed via ... area broadcast.
ZOS Request area routing for messages for ... ? Area routing for messages for ... is ...
ZOT   Transmit or handle this message at the lower precedence to the station or address designator(s) which follow(s).
ZOU How should traffic for ... be routed ? Route traffic for ... through ... (on ... kHz (or MHz)).
ZOV   Station designation preceding this operating signal is the correct routing for this message rerouted by ...
ZOW   Broadcast this message at special watch keeping periods for ships with (1) one radio operator; (2) two radio operators.
ZOX   Place this message (or message ...) on ... (1) morse/CW; (2) RATT; submarine broadcast indicated by following specific broadcast designator(s) ...
ZOY   Relay this message only to the station(s) whose designation(s) precede this operating signal.
ZOZ   Relay this message (or message ...) in its present form without decryption.
ZPA   Printer line feed not received.
ZPA *  Your speech is distorted.
ZPB   Your transmitter has strong radiation while idling.
ZPC   Printer carriage return not received.
ZPC *  Your signals are ... (1) fading badly; (2) fading slightly; (3) good for ... words per minute; (4) getting stronger; (5) getting weaker.
ZPD Is your signal as checked by monitor ... satisfactory (1) locally; (2) as radiated ? My signal as checked by monitor ... is satisfactory (1) locally; (2) as radiated.
ZPE   Punch everything.
ZPE *  Maximum power is now being radiated.
ZPF   Printer motor fast.
ZPF *What is the readibility of the signals of the group (net) (or of ...) ? The Readibility of the signals of the group (net) (or of ...) is ... (1 - 5).
ZPG What is the signal strength(s) of group (net) (or of ...) ? Signal strength(s) of group (net) is (are) (or of ...) is ... (1 - 5).
ZPH   This interrupted transmission is canceled. A complete retransmission from this station will follow without request.
ZPJ   This is a SUBOPAUTH edited version, either addressees and/or non-essential text have been removed from this message. Subsequent delivery of the originators unedited message is not intended unless requested.
ZPK   This is a SUBOPAUTH edited version, either addressees and/or non-essential text have been removed from this message. The originators unedited message will be delivered by other means.
ZPL   Request unedited versions of edited messages, broadcast number(s) ... be forwarded by means other than the submarine broadcast.
ZPN   IFF switched ON in distress position.
ZPO   Send plain once.
ZPO *  The text of this message is to be relayed in precisely the same format as that in which it is received. No characters or machine functions are to be added, inserted or deleted and the relative positions of the groups are to be retained.
ZPP   Punch plain only.
ZPP *  Message which follows is a submarine surfacing signal to be cleared on calling frequency.
ZPR   Rerun slip at present running.
ZPR *  I have ... messages (precedence) prepared in tape relay format for you (or for ...). (Consideration should be given to receiving this message directly on to a printing perforator/typing perforator).
ZPS   Printer motor slow.
ZPT   Send plain twice.
ZPT *  This transmission is a transmitter pre-acceptance trial. Request expeditious strength and readability reply.
ZPU   If more than one tropical wind warning message in this sequence is awaiting transmission, transmit highest serial number first. (Sequence/Serial is understood to include tropical warning name or number and consecutive warning number).
ZPV   If the earlier wind warnings identified by DTG(s) following this signal are awaiting transmission, file those warnings without further transmission.
ZPW   This message canceled at time indicated. File without further transmission.
ZPX   This message (or message ...) is forwarded to you for screening and determination of need for broadcast promulgation. Advise broadcast control commander of recommended message disposition.
ZPY   This message (or message ...) has been screened by command authority and requires broadcast delivery.
ZPZ   This message has been forwarded ... (number of times) by stations within this network. Note: the number shall be incremented by one each time the message is relayed within the network. The OPSIG will be removed prior to the message exiting the network.
ZQA   The landing lights at the aerodrome (or at the aerodrome at ...) are out of order.
ZQB What is the magnetic direction in which landing is to be made ? The magnetic direction in which landing is to be made is ... degrees.
ZQC Are you (or is ...) ... (1) airborne; (2) waterborne; (3) on land ? I am (or ... is) ... at ... (time). (1) airborne; (2) waterborne; (3) on land.
ZQD Am I to carry out the procedure appropriate to the use of the ... (facility) ? You are to carry out the procedures appropriate to the use of the ... (facility).
ZQE What is your desired rate of descent expressed in hundreds of feet per minute ? My desired rate of descent is ... hundreds of feet per minute.
ZQF What is the length in yards of the runway in use ? The length of the runway in use is ... yards.
ZRA   Reverse auto tape.
ZRA *How does my frequency check ? Your frequency is ... (1) correct; (2) slightly (or ... Hz (or kHz)) high; (3) slightly (or ... Hz (or kHz)) low; (4) stable on steady mark; (5) stable on steady space; (6) unstable; (7) erratic.
ZRB   Relayed signals bad, adjust receiver.
ZRB *  Check your (or ...'s) frequency on this circuit (or on ... kHz (or MHz)).
ZRC Can you receive code ?  
ZRC *Shall I tune my transmitter to ... (1) proper frequency; (2) zero beat with your (or ...) transmitter ? Tune your transmitter to ... (1) proper frequency; (2) zero beat with my (or ...) transmitter.
ZRD What is the frequency of the ... radio facility now in operation ? The frequency of the ... radio facility now in operation is ...
ZRE On what frequency do you hear me best ? I hear you best on ... kHz (or MHz).
ZRF Will you send tuning signal on your present frequency (or on ... kHz (or MHz)) for one minute or until 'AS' is given? I am about to send tuning signal on my present frequency (or on ... kHz (or MHz)).
ZRG When will a change of frequency (to ... kHz (or MHz)) be necessary ? A change in frequency (to ... kHz (or MHz) will be necessary at approximately ...
ZRH Is my frequency shift correct ?Your frequency shift is ... (1) too wide; (2) too narrow; (3) not linear; (4) correct; (by Hz).
ZRJ Will you check your ... ?I will check my ...
ZRK   Reversed keying.
ZRK *Shall I revert to single channel working ? Revert to single channel working.
ZRL   Rerun slip before new running.
ZRL *Are you working on the correct code ? Note: this meaning applies only to frequency shift diplex. I am working on the correct code. Note: this meaning applies only to frequency shift diplex.
ZRM   Please remove modulation from ...
ZRM *Can you receive both sidebands of my independent sideband transmissions ? I can receive ... (1) the upper sideband; (2) the lower sideband; (3) both sidebands.
ZRN   Rough note.
ZRN *Do you intend to transmit on ... (1) the upper sideband (USB); (2) the lower sideband (LSB); (3) both sidebands independently (ISB) ? I intend to transmit on ... (1) the upper sideband (USB); (2) the lower sideband (LSB); (3) both sidebands independently (ISB).
ZRO Are you receiving OK ?  
ZRO *Can you read me on ... (1) channel A ...; (2) channel B ...; (3) channel(s) ...; (4) all channels ? I can read you on ... (1) channel A ...; (2) channel B ...; (3) channel(s) ...; (4) all channels; (5) no channels.
ZRP   Transfer signal on channel ... to channel ... (should only be used when order originates from a third working channel. See ZRV for use between directly connected working channels).
ZRQ   Change to other sideband.
ZRR   Run reversals.
ZRR *  Message(s) ... number(s) ... will no longer be broadcast but are effective and of interest (to units indicated).
ZRS   Rerun message number ...
ZRS *  Your carrier is ... (1) over-suppressed; (2) under-suppressed.
ZRT   Revert to traffic.
ZRT *  Radiate full unmodulated power for ... minutes.
ZRU Are my tone frequencies correct ? Your tones for ... (1) marking and spacing are high; (2) marking and spacing are low; (3) marking and spacing are correct.
ZRV   Transfer signal to channel ...
ZRW   Retransmit phasing signal ... (1) you did not synchronize; (2) check your daily key setting.
ZRY   Rerun test slip with RYs, please.
ZSA May I ascend to ... (height) ? You may ascend to ... (height).
ZSB May I descend to ... (height) ? You may descend to ... (height).
ZSC   Switch on IFF.
ZSD   IFF switched OFF.
ZSE Do you have glider in tow ? (1) we have glider in tow; (2) we are forced to release glider at (approximate position) ...
ZSF   Send faster.
ZSF *  Switch off ... (1) IFF; (2) IFF sets for 10 minutes in area denoted except for ships whose call signs follow.
ZSG May I make an approach using the facility indicated ? You may approach using the facility indicated.
ZSH   Static heavy here.
ZSI   Please furnish signal intensity.
ZSI *  You are ... (1) to maintain height of ... feet and report over ... (call sign) range station; (2) to hold on ... leg of the beam ... (call sign) range station at height ... feet.
ZSM   Microvolt input to receiver is ...
ZSN   Give SINPO report on ...
ZSO   Transmit slips once.
ZSO *  Send tapes (or message) ... (1) once; (2) twice.
ZSR   Your signal strong and readable.
ZSS   Send slower.
ZST   Transmit slips twice.
ZSU   Your signals are unreadable.
ZSV   Your speed varying.
ZTA   Transmit by auto.
ZTA *  (1) radio; (2) visual; (3) land line; (4) teletypewriter (teleprinter); (5) telephone; (6) automatic; (7) facsimile; (8) shore telephone; (9) shore teleprinter; (10) radio teletypewriter; (11) satellite.
ZTB   (1) transmitter-distributor; (2) autohead; (3) perforator; (4) reperforator; (5) printer; (6) undulator; (7) keyboard; (8) frequency shift keyer; (9) multiplexing carrier base; (10) on-line crypto device.
ZTC (1) Does my ... appear to be faulty ? (2) Is your ... faulty ? (1) Your ... appears to be faulty; (2) my ... is faulty.
ZTD Shall I use ... ? Use ...
ZTE Are you (or is ...) able to use ... ? I am (or ... is) able to use ...
ZTF   Send fast and twice.
ZTF *Are repairs completed ? Repairs ... (1) completed; (2) uncompleted. Estimated completion time ... minutes; (3) cannot be completed because ...
ZTG   ... (class of emission/type of transmission as indicated in chapter 6).
ZTH   Transmit by hand.
ZTI   Transmission temporarily interrupted.
ZTI *  (1) receiver; (2) transmitter; (3) power supply; (4) antenna system; (5) radio direction finder.
ZTJ   Cease using ...
ZTK Are you (or is ...) connected to ... ? I am (or ...is) connected to ...
ZTL Are you (or is ...) about to disconnect ? I am (or ... is) about to disconnect.
ZTM   I am (or ... is) unable to use ...
ZTN What is my bias distortion ? Your bias distortion is ... (1) excessive; (2) ... percent (marking); (3) ... percent (spacing); (4) ... percent (total distortion).
ZTO Is my charatcer formation correct ? Your character formation is ... (1) correct; (2) defective in the start element; (3) defective in the 1st unit; (4) defective in the 2nd unit; (5) defective in the 3rd unit; (6) defective in the 4th unit; (7) defective in the 5th unit; (8) defective in the stop element.
ZTP What is the duration of your modulation cycle ? The duration of my modulation cycle is ... 50 Baud Euqipment: (1) 148 milliseconds (7.42 units) fast; (2) 150 milliseconds (7.5 units) correct; (3) 152 milliseconds (7.6 units) slow; (4) ... erratic per character. 45.5 Baud Euqipment: (1) 161 milliseconds (7.35 units) fast; (2) 163 milliseconds (7.42 units) correct; (3) 165 milliseconds (7.5 units) slow; (4) ... erratic per character.
ZTQ Will you ... (1) get the circuit engineer/facility control technician to speak on this circuit (or circuit ...); (2) hand the line over to the circuit engineer/facility control technician for check ? I will ... (1) get the circuit engineer/facility control technician to speak on the circuit; (2) hand the line over to the circuit engineer/facility control technician for check and call you when check has been completed.
ZTR Will you ... (1) disconnect your equipment from line and carry out local test, reconnecting to line in ... minutes; (2) connect your transmit line to your receive line to enable me to carry out a loop test for ... minutes ? I will ... (1) disconnect (or I am disconnecting) my equipment from line and carry (or to carry) out local test, reconnecting to line in ... minutes; (2) connect my transmit line to my receive line to enable you to carry out a loop test for ... minutes.
ZTS Is the line satisfactory ? The line is ... (1) satisfactory; (2) unsatisfactory.
ZTT   Fixed aerial (1) omni-directional ...; (2) rotatable; (3) directional.
ZUA   Conditions unsuitable for automatic recording.
ZUA *Request a timing signal now (or at ...). Timing signal will be transmitted now (or at ...). The numerals indicating the time will be followed by a five-second dash terminating exactly at the time indicated.
ZUB   We have been unable to break you.
ZUB *  At ...
ZUC   Unable to comply, will do so at ...
ZUC *  From ... to ...
ZUD   Until further orders (or until ...).
ZUE   Affirmative (Yes).
ZUF   Air raid ... (1) waring; (2) in progress; (3) all clear.
ZUG   Negative (No).
ZUH   Unable to comply.
ZUI   Your attention is invited to ...
ZUJ   Stand by.
ZUK ... (Appointment Code) desires key conversation on this circuit with ... (Appointment Code). Will you indicate when you are ready ? ... (Appointment Code) is now ready to begin key conversation with ... (Appointment Code).
ZVA   Station called is responsible for relay or delivery to all stations in line two (2) or to stations indicated.
ZVB   Varying bias.
ZVB *What was your time over last compulsory reporting point, and ETA at next compulsory reporting point ? My time over last compulsory reporting point was ... and ETA at next compulsory reporting point is ...
ZVE What are the security conditions of your termination(s) of this channel (or ... channel/circuit designated) ? Security conditions at my termination(s) of this channel (or ... channel/circuit designated) are ... (1) secured for Restricted; (2) secured for Confidential; (3) secured for Secret; (4) secured for Top Secret. Note: the answer to this signal may only be passed on circuits cleared for classified traffic.
ZVF   Signals varying in frequency.
ZVF *  This channel (or ... channel/circuit designated) is unserviceable for classified traffic.
ZVP   Send VVVs please.
ZVQ   This message, relating to a warning, an alert, distress, or an emergency, is authorized to be relayed via the facilities of your network without prior arrangement.
ZVR   Retransmit this message (or message ...) at once to all subordinate stations.
ZVS   Signals varying in intensity.
ZWB   Indicate name of ... (1) operator on watch; (2) senior rating on watch; (3) operator who transmitted last message (or message ...). Note: this signal is authorized for use in connection with operator training only; it may not be used for any other purpose.
ZWC   Wipers or clicks here.
ZWC   The following is to be taken as applying to personnel on watch only.
ZWD   Carry out communication ... (visual exercise number ... at ... senior officer (or ...) is to conduct).
ZWE   Voluntary exercise (number ...) may be carried out now (or at ...).
ZWF   Incorect.
ZWG   You are correct.
ZWH   Try again.
ZWI   Answer last question (or question ...).
ZWJ   Stations are to answer ... taking the following duties ... A, ...B, ...C, ... etc.
ZWK   Following is answer to the last question (or question ...).
ZWL   No forwarding action to the designation(s) immediately following is required.
ZWM   Correct answer to last question (or question ...) is ... (or will be found in ...).
ZWN   Correct version of the part of the last message (or message ...) which was sent incorrectly is ... (or will be found in ...).
ZWO   Send words once.
ZWO *  Following message (or question, or exercise) is for the exercise of ... (1) junior operators; (2) senior operators; (3) ratings on watch.
ZWP   A junior operator is to carry out ... (1) a standard flashing exercise; (2) a standard semaphore exercise; (3) a standard radio-telegraphy transmitting exercise; (4) a standard radio-telegraphy receiving exercise.
ZWR   Your signals weak but readable.
ZWS   Wavelength (frequency) is swinging, 1...5.
ZWT   Send words twice.
ZXA   Adjust to receive speed ... (fax)
ZXA *  The following group is a call sign, delivery group or address group. (Used in plain language texts of messages other than procedure messages).
ZXB   Station(s) to whom this message is routed obtain a complete copy of this interrupted transmission by addressing a service message to the originating station.
ZXC   Pix ... conditionally accepted.
ZXC *  This transmission has been interrupted. A retransmission will follow without request. (Must be followd immediately by valid end of message sequence).
ZXD   Send dashes, please. (fax)
ZXD *  This message is to be delivered to the addressee(s) in tape form.
ZXE   Reserved for future use by NACOSA/ISSC.
ZXF   You are floating fast. (fax)
ZXF *  (1) For peacetime operations: This message has been generated/mediated by a COSMIC TOP SECRET ATOMAL System High SCARS II System. The Maximum security classification authorized without off-line encryption released from SCARS II into the NICS TARE network is NATO SECRET. ATOMAL information at any security classification level released into the NICS TARE network requires also off-line encryption. (2) For TTW/Wartime operations after authorization from Operational Commander: This message has been generated/mediated by a COSMIC TOP SECRET ATOMAL SYSTEM HIGH SCARS II SYSTEM.
ZXG   This MSG has been generated/mediated by a NATO CONFIDENTIAL System High automated data processing system.
ZXH   Limits high, reduce ... cycles. (fax)
ZXH *  This MSG has been generated/mediated by a NATO SECRET System High automated data processing system.
ZXI   This critical SCARS II MSG should be given precedence over other Flash messages. Note: signals listed are reserved for use by NACOSA.
ZXJ   You are jumping out of phase. (fax)
ZXK Is your synchronizing correct ? (fax)  
ZXK *  Station called relay this message (or message ...) to ... in addition to predetermined responsibilities.
ZXL   Limits are low, increase ... cycles. (fax)
ZXO   Last run defaced due to ... (fax)
ZXO *  Request you obtain retransmission of messages ... from station ...
ZXP   Go ahead with Pix.
ZXP *  I have for you ... (1) a request for direct air support; (2) a reply to a support request; precedence is ...
ZXQ   I have for you ... (1) a request for tactical reconnaissance; (2) a request for photographic reconnaissance; (3) a request for artillery reconnaissance; precedence is ...
ZXR   Intensive flag signaling will take place shortly (or in ... minutes).
ZXS   You are floating slow. (fax)
ZXS *  Message which follows is to be handled by ... (1) officer emergency cryptographic team; (2) ratings emergency cryptographic team; (3) senior communications rating; (4) junior communications rating; (5) coder (educational).
ZXT   This message is not to be transmitted by radiotelegraph or radiotelephone in any form over part of its route.
ZXV   Your modulation is varying. (fax)
ZXW   This message has been delivered to all action addressees whose designations follow this operating signal.
ZXX   This message has been delivered to all information addressees whose designations follow this operating signal.
ZXY   Transmit this message to the addressee(s) indicated by the numeral(s) following ... All addressees are to be counted consecutively as they appear (numbers to be separated by the Separative Sign).
ZYA   Cease traffic, send As on A channel. (multiplex)
ZYC   Cycling on ARQ, errors stored your end. (multiplex)
ZYK   Check your keying on channel ... (multiplex)
ZYM   Change from single printer to multiplex.
ZYN   Make bias neutral. (multiplex)
ZYO   Message originated with mobile units.
ZYP   Change from multiplex to single printer.
ZYR   Please put ... on MUX revolutions.
ZYS What is your speed of transmission ? The speed of transmission is ...
ZYT   Check your thyratrons.
ZYT *  Forward this message without service action.
ZYX   Revert to MUX frames ... channels.
ZZA   Tell name of operator who has transmitted last msg (or msg ...).
ZZD&   Readibility is ... ("ich hoere Sie gut"); QRK.
ZZF   Incorrect.
ZZG   You are correct.
ZZH   Try again.
ZZN   Message is a drill message for ... (1) beginning operators (2) advanced operators (3) operators on watch.
ZZO   Beginning operator.
ZZS&   Change freq. to ... ("gehen Sie auf ..."); QSY/QDW.