Z-CODES
Press the appropriate button on the left to go to another section of this site or select Q-Codes, Morse Code, Baudot Code or Abbreviations and Jargon to see the appropriate list. If there are no buttons on the left, you probably got directly to this page via a search engine. Select normal access to go to the G3NPF/M1AIM home page. The Z-Code was originally developed as a service code by Cable & Wireless Ltd. for usage in the commercial communications business. NATO military Z-signals are completely different from the old Cable & Wireless codes. Z-Codes are mainly used over commercial and military teleprinter, facsimile and high speed automatic telegraphy links and are not normally used by Radio Amateurs, even when using RTTY, but the list is included for general interest. The list and usage data was compiled by Ralf D.Kloth, DL4TA, and is reproduced here with his permission. We are grateful to Ralf for this, as he spent a considerable amount of time and effort researching various sources in order to produce his list. The NATO military Z-signals, ZAA...ZXZ, are defined in ACP 131, but the series ZYA...ZZZ is reserved for the temporary or permanent assignment of meanings on an intra-military basis by any nation, service or command. In the following table, a non-annotated code denotes the original Cable & Wireless usage, * indicates NATO military usage (ACP-131(E), 1997) and ** indicates Russian military usage. As the majority of Z-Codes are not normally used as questions, their meanings are given with the answer, advice or information form shown first, with the question form shown in a second column, if appropriate. Z signals shall be read as questions when followed by the interrogation signal (IMI) in civil use or preceeded by the prosign (INT) in NATO military use.
Note that the numbers 1...5 following a Z signal have the following meanings:-
(1) very slight
(2) slight
(3) moderate
(4) severe
(5) extreme
List of Z-Codes
Code Advice, Information or Answer Question
ZAA* You are not observing proper circuit
disciplin.
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* I am about to patch you through to ... Will you patch me through
(via ...). to ... (via you or ...) ?
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* Work ... Shall I Work ...
(1) simplex; (1) simplex;
(2) duplex; (2) duplex;
(3) diplex; (3) diplex;
(4) multiplex; (4) multiplex;
(5) single sideband; (5) single sideband;
(6) with automatic error (6) with automatic error
correction system; correction system;
(7) without automatic error (7) without automatic
correction system; error correction
(8) with time and frequency system;
diversity modem ? (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* Teletype range taken on your signal(s) What is teletype range taken
is ... to ... on my signal(s) ?
ZAV* Transmit traffic for me (or for ...) by
broadcast method until further directed
(or until ...).
ZAW* Transmit 12 inches of blank tape as short Shall I transmit 12 inches of
intervals ar ... words per minute. 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* Delay (or bad transmission) due to ... What is cause of delay (or
of bad transmission) ?
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* The estimated errors per thousand printed What are the estimated errors
characters in your signals per thousand characters in my
(or those of ...) is ... signals (or those of ...) ?
(1) greater than 13;
(2) 7 to 12;
(3) 1 to 6;
(4) nil.
ZBK* I am receiving your traffic ... Are you receiving my traffic
(1) clear 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* I have (or ... has) ... (numeral followed Of what precedence(s) and
by precedence prosign for each pre- for whom is (are) your
precendece) message(s) for you message(s) ?
(or for ...).
ZBP* Your ...
(1) characters are indistinct;
(2) spacing is bad.
ZBQ* Message ... was received at ... on ... kHz When and on what frequency
(or MHz). was message ... received ?
ZBR Break circuit, retuning.
ZBR* Send by ... Shall I send by ...
(1) direct (R) method; (1) direct (R) method;
(2) broadcast (F) method; (2) broadcast (F) method;
(3) intercept (I) method; (3) intercept (I) method;
(4) repeat back (G) 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* Text group(s) ... should be counted as How do you count following
... group(s). text group(s) ... ?
ZBU* Report when you are in radio communication
with ...
ZBV* Answer me (or ...) on ... kHz (or MHz).
ZBW* I am (or ... is) shifting to transmit on Will you shift (or ask ... to
... kHz (or MHz). shift) to transmit on ... kHz
(or MHz) ?
ZBX* I am (or ... is) shifting to receive on Will you shift (or ask ... to
... kHz (or MHz). shift) 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* The printing acceptability of your signals What is the printing
(or those of ...) is ... acceptability of my signals
(1) unacceptable - totally corrupt; (or those of ...) ?
(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* My frequency modulation deviation is ... What is your frequency
modulation deviation ?
ZCH* My tracking mode is ... What is your tracking mode ?
(1) auto track;
(2) manual tracking;
(3) hand barring.
ZCI Circuit interrupted. Running and available.
ZCI* My ... What is your ... ?
(1) is ... watts; (1) total output power;
(2) is ... %; (2) quality meter reading;
(3) is ... accesses; (3) number of accesses;
(4) is ... watts. (4) frequency modulation
access power.
ZCJ* I am experiencing equipment trouble with Are you experiencing equipment
my ... trouble ?
(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* Loop your ... Shall I loop my ... ?
(1) spread spectrum modulator (1) spread spectrum
channel ...; modulator channel
(A/B);
(2) line modem; (2) line modem;
(3) time division multiplex equipment; (3) time division
multiplex equipment;
(4) frequency division multiplex (4) frequency division
equipment. multiplex equipment.
ZCL Transmit call letters intelligibly.
ZCL* I have checked speed setting on ... Have you checked speed setting
(channel/circuit). of all equipment on ...
(channel/circuit) ?
ZCM* Carry out ... on satellite ... May I carry out ... on
(1) spread spectrum modulation satellite ... ?
back-to-back check; (1) spread spectrum
(2) range measurement; modulation back-to-
(3) power balance. back check;
(2) range measurement;
(3) power balance.
ZCN* I am ready to synchronize spread spectrum Are you ready to synchronize
access ... 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* Last message (or message ...) requires a Does the last message (or
signal of execution. message ...) require 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* I have a msg containing ... groups to How many groups does your
transmit to you (or to ...). message contain ?
ZDK* Following repetition (of ...) is made in Will you repeat message ...
accordance with your request. (or portion ...) ?
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 in 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 orders (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* Message ... Have you received
(1) not received; message ... ?
(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* This message is correction to message ... Is message ... a correction
(transmitted by ...). to message ... which was
Note: May only be used in conjunction previously transmitted with
with ZDG. doubtful or missing groups
(words) ?
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* Executive signal ("Execute") for last Have you received (or sent) the
message (or following message) has been executive signal ("Execute")
made (or was made at ...). for message ... ?
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* There is no reply to message ... Is there any 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* Message ... (or station serial number ...) Does message ... (or station
(1) does not concern you (or ...); serial number ...) concern me
(2) no longer concerns you (or ...). (or ...) ?
ZFL* Following traffic was addressed to you Was there any traffic
on ... broadcast schedule between serial addressed to me on ...
numbers ... and ... 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* Your callsign for use on this circuit What is my call sign for use
is ... on this circuit only ?
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* Call sign of ... is ... What is call sign of ...
(1) friendly striking force aircraft; (1) friendly striking
(2) friendly shadowing aircraft; force aircraft;
(3) incoming vessel; (2) friendly shadowing
(4) senior officer present afloat (or aircraft;
Officer in tactical command); (3) incoming vessel;
(5) ship acting as flagship for ... (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* I will call you again as soon as possible When will you call me again
(or at ...) on present frequency (or on present frequency (or
on ... kHz (or MHz)). on ... kHz (or MHz)) ?
ZGK* Call me again at ... on present frequency When shall I call you on
(or on ... kHz (or MHz)). present frequency (or
on ... kHz (or MHz)) ?
ZGL* ... will answer calls for me (or for ...).
ZGM* I have (or ... has) been unable to Did you (or ...) hear ...
communicate with ... (since ...). (at ...) ?
ZGN* Nothing was heard from you (or ...) When was I (or ...) last
(since ...). heard ?
ZGO* Your number is ...; answer after number What is my number and
... (numbers to be separated by sequence in answering ?
separative signs.
ZGP Please give priority.
ZGP* Answer calls for me on present frequency
(or on ... kHz (or MHz)).
ZGS Your signals are getting stronger.
ZGW Your signals are getting weaker.
ZHA How are conditions for auto reception ?
ZHA* Decrease frequency very slightly Shall I decrease frequency
(or ... kHz) to clear interference. very slightly (or ... kHz)
to clear interference ?
ZHB* Increase frequency very slightly Shall I increase frequency
(or ... kHz) to clear interference. very slightly (or ... kHz)
to clear interference ?
ZHC How are your receiving
conditions ?
ZHM Harmonic radiation from transmitter ...
ZHN* Your automatic transmissions are ... How do you receive my
(1) good; automatic transmission ?
(2) fair;
(3) unreadable.
ZHO* My speed of automatic transmission in ... What is your speed of
(1) revolutions per minute; automatic transmission in ...
(2) words per minute; (1) revolutions per
(3) bauds; minute;
is ... (2) words per minute;
(3) bauds ?
ZHP* Automatic reception is prevented by ... What is preventing automatic
reception ?
ZHQ* Please listen for me on ... kHz (or MHz)
and transmit to me on ... kHz (or MHz).
ZHR* Your speed of automatic transmission is ...
(1) fast;
(2) slow;
(3) erratic;
(4) correct.
Is my speed of automatic transmission
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* Station serial number(s) or channel What is (are) station serial
number(s) of last message(s) transmitted number(s) or channel number(s)
to you (or to ...) is (are) ... of last message(s) you
transmitted to me (or
to ...) ?
ZID* Station serial number(s) or channel What is (are) station serial
number(s) of last message(s) received from number(s) or channel number(s)
you (or from ...) is (are) ... of last message(s) you
received from me (or
from ...) ?
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* Number(s) ... (to ...) is (are) blank. Is (are) number(s) ... (to ...)
blank ?
ZIH* Repeat headings of message numbers ...
to ... transmitted by you (or ...) to check
serial numbers.
ZII* My (or ...'s) message number ... had What was ... of your (or ...'s)
following ... number ... ?
(1) date-time-group; (1) date-time group;
(2) filing time. (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* Use channel number(s) ... What channel number(s) should
I use ?
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* Close down visual watch now (or at ...). May I 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* Call signs of the ships in company with me What are the call signs of the
are ... (for visual use only). ships in company with you ?
ZJJ* Use double-flash procedure.
ZJK* I am (or ... is) visual guard for ... Are you (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* I am (or ... is) controlling station (net Who is controlling station
control station) on this frequency (or (net control station) on this
on ... kHz (or MHz)). frequency (or on ... kHz
(or MHz)) ?
ZKB* It is necessary to obtain the permission Is it necessary to obtain the
of the controlling station (net control permission of the controlling
station) before transmitting messages. 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* Take control of net (for ...) (until ...). Shall I 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* I (or ...) observed schedule with ... Did you (or ...) observe
(at ...). schedule with ... (at ...) ?
ZKI Set watch on ... kHz (or MHz) ...
(1) continuous;
(2) until further notice.
ZKJ* (1) close down (until ...); May I 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* I am (or ... is) radio guard for ... Are you (or is ...) radio
(on ... kHz (or MHz)). 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* I am (or ... is) maintaining watch on On what frequencies are you
... kHz (or MHz). (or ...) maintaining watch ?
ZKS* Following stations are keeping watch on What stations are keeping
... kHz (or MHz) (or are in net). 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* Transmit at ... revolutions per minute. What drum rotation speed shall
(1) 30; I use ?
(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* Transmit ... Shall I transmit ...
(1) negative; (1) negative;
(2) positive. (2) positive ?
ZLH* I am going to transmit map(s) ... (... Will you transmit map(s) ...
area ... time ... type). (... area ... time ... type) ?
ZLI* Reverse material on drum and rerun until
I break you.
ZLJ* Use ... What size lettering shall I
(1) standard telegraphic typewriter; use ?
(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* The following ... facility(ies) is (are) Is (are) facility(ies) ...
operative at this station (or at ...). operative at your station (or
(1) homing beacon; at ...) ?
(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* The magnetic line(s) of shoot of the ... What is (are) the magnetic
(facility) is (are) ... degrees. line(s) of shoot of the ...
(facility) ?
ZLS We are suffering from lightning storm.
ZMA* Bearing of unknown station (or station What was bearing of unknown
using call sign ...) was ... (at ... time) station (or station using call
class ... (on ... kHz (or MHz)). sign ...) at ... (time) (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* Bearing of station now transmitting (or Will you endeavor to obtain a
of ...) (on ... kHz (or MHz)) was ... direction finding bearing of
(class ...) sense determined at ... station now transmitting (or
of ...) (on ... kHz (or
MHz)) ?
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* I am about to send my call sign and dashes Will you send your call sign
of five-seconds duration at intervals in and dashes of five-seconds
order that you (or ...) may home on me. duration at intervals in order
that I (or ...) may home on
you ?
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 a moment.
ZMO* Your position by direction finding cross What is my position by
bearings from nearest landmark (or from direction finding bearing
...) is ... (class ...) at ... (hours). from nearest landmark (o
from ...) ?
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* The grid course for you to steer to reach What is the grid course for
me (or ...) is ... degrees at ... hours. me to steer to reach you
(or ...) ?
ZNA* You are encrypting ... incorrectly.
(1) operating signals;
(2) radio call signs;
(3) address groups.
ZNB No breaks, we send twice.
ZNB* Authentication (of ...) is ... What is authentication of ...
(1) message ... (1) message ...;
(2) last transmission (2) last transmission;
(3) ... (3) ... ?
ZNC No communications with ...
ZNC* All transmissions will be authenticated ...
(1) on all circuits;
(2) on this circuit;
(3) on ... frequency.
ZND* You 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 is 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* Give me your message. I will dispose of Can you accept message
it ... for ... ?
(1) on line; (1) on line;
(2) off 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 Traffic on hand. What traffic have you 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* Area routing for messages for ... is ... Request area routing for
messages for ... ?
ZOT* Transmit or handle this message at the lower
precedence to the station or address
designator(s) which follow(s).
ZOU* Route traffic for ... through ... How should traffic for ... be
(on ... kHz (or MHz)). routed ?
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* My signal as checked by monitor ... is Is your signal as checked by
satisfactory monitor ... satisfactory
(1) locally; (1) locally;
(2) as radiated. (2) as radiated ?
ZPE Punch everything.
ZPE* Maximum power is now being radiated.
ZPF Printer motor fast.
ZPF* The Readibility of the signals of the group What is the readibility of the
(net) (or of ...) is ... (1 - 5). signals of the group (net)
(or of ...) ?
ZPG* Signal strength(s) of group (net) is (are) What is the signal strength(s)
(or of ...) is ... (1 - 5). of group (net) (or of ...) ?
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* The magnetic direction in which landing is What is the magnetic
to be made is ... degrees. direction in which landing
is to be made ?
ZQC* I am (or ... is) ... at ... (time). Are you (or is ...) ...
(1) airborne; (1) airborne;
(2) waterborne; (2) waterborne;
(3) on land. (3) on land ?
ZQD* You are to carry out the procedures Am I to carry out the
appropriate to the use of the ... procedure appropriate to the
(facility). use of the ... (facility) ?
ZQE* My desired rate of descent is ... What is your desired rate of
hundreds of feet per minute. descent expressed in hundreds
of feet per minute ?
ZQF* The length of the runway in use is What is the length in yards
is ... yards. of the runway in use ?
ZRA Reverse auto tape.
ZRA* Your frequency is ... How does my frequency check ?
(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* Tune your transmitter to ... Shall I tune my transmitter
to ...
(1) proper frequency; (1) proper frequency;
(2) zero beat with my (or ...) (2) zero beat with your
transmitter. (or ...)
transmitter ?
ZRD* The frequency of the ... radio facility What is the frequency of
now in operation is ... the ... radio facility now
in operation ?
ZRE* I hear you best on ... kHz (or MHz). On what frequency do you
hear me best ?
ZRF* I am about to send tuning signal on my Will you send tuning signal
present frequency (or on ... kHz (or MHz)). on your present frequency
(or on ... kHz (or MHz)) for
one minute or until 'AS' is
given ?
ZRG* A change in frequency (to ... kHz When will a change of
(or MHz) will be necessary at frequency (to ... kHz
approximately ... (or MHz)) be necessary ?
ZRH* Your frequency shift is ... Is my frequency shift
(1) too wide; correct ?
(2) too narrow;
(3) not linear;
(4) correct;
(by Hz).
ZRJ* I will check my ... Will you check your ... ?
ZRK Reversed keying.
ZRK* Revert to single channel working. Shall I revert to single
channel working ?
ZRL Rerun slip before new running.
ZRL* I am working on the correct code. Are you working on the correct
Note: this meaning applies only to code ?
frequency shift diplex. Note: this meaning applies
only to frequency shift diplex.
ZRM Please remove modulation from ...
ZRM* I can receive ... Can you receive both sidebands
(1) the upper sideband; of my independent sideband
(2) the lower sideband; transmissions ?
(3) both sidebands.
ZRN Rough note.
ZRN* I intend to transmit on ... Do you intend to transmit
on ...
(1) the upper sideband (USB); (1) the upper sideband
(USB);
(2) the lower sideband (LSB); (2) the lower sideband
(LSB);
(3) both sidebands independently (ISB). (3) both sidebands
independently (ISB) ?
ZRO Are you receiving OK ?
ZRO* I can read you on ... Can you read me on ...
(1) channel A ...; (1) channel A ...;
(2) channel B ...; (2) channel B ...;
(3) channel(s) ...; (3) channel(s) ...;
(4) all channels; (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* Your tones for ... Are my tone frequencies
(1) marking and spacing are high; correct ?
(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* You may ascend to ... (height). May I ascend to ... (height) ?
ZSB* You may descend to ... (height). May I descend to ... (height) ?
ZSC* Switch on IFF.
ZSD* IFF switched OFF.
ZSE* (1) we have glider in tow; Do you 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* You may approach using the facility May I make an approach using
indicated. 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 is strong and readable.
ZSS Send slower.
ZST Transmit slips twice.
ZSU Your signals are unreadable.
ZSV Your speed is 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) Your ... appears to be faulty; (1) Does my ... appear to be
(2) my ... is faulty. faulty ?
(2) Is your ... faulty ?
ZTD* Use ... Shall I use ... ?
ZTE* I am (or ... is) able to use ... Are you (or is ...) able to
use ... ?
ZTF Send fast and twice.
ZTF* Repairs ... Are repairs completed ?
(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* I am (or ...is) connected to ... Are you (or is ...) connected
to ... ?
ZTL* I am (or ... is) about to disconnect. Are you (or is ...) about to
disconnect ?
ZTM* I am (or ... is) unable to use ...
ZTN* Your bias distortion is ... What is my bias distortion ?
(1) excessive;
(2) ... percent (marking);
(3) ... percent (spacing);
(4) ... percent (total distortion).
ZTO* Your character formation is ... Is my character formation
(1) correct; 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* The duration of my modulation cycle is ... What is the duration of your
50 Baud Equipment: modulation cycle ?
(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 Equipment:
(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* I will ... Will you ...
(1) get the circuit engineer/facility (1) get the circuit
engineer/facility
control technician to speak on control technician
the circuit; to speak on this
(2) hand the line over to the circuit circuit (or circuit
engineer/facility control ...);
technician for check and call you (2) hand the line over to
when check has been completed. the circuit engineer/
facility control
technician for check ?
ZTR* I will ... Will you ...
(1) disconnect (or I am disconnecting (1) disconnect your
my equipment from line and carry equipment from line
(or to carry) out local test, and carry out local
reconnecting to line in ... test, reconnecting to
minutes; line in ... minutes;
(2) connect your transmit
(2) connect my transmit line to my line to your receive
receive line to enable you to line to enable me to
carry out a loop test for ... carry out a loop test
minutes. for ... minutes ?
ZTS* The line is ... Is the line satisfactory ?
(1) satisfactory;
(2) unsatisfactory.
ZTT* Fixed aerial
(1) omni-directional ...;
(2) rotatable;
(3) directional.
ZUA Conditions unsuitable for automatic
recording.
ZUA* Timing signal will be transmitted now Request a timing signal now
(or at ...). The numerals indicating the (or at ...).
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) is now ready to ... (Appointment Code) desires
begin key conversation with ... key conversation on this
(Appointment Code). circuit with ... (Appointment
Code).
Will you indicate when you are
ready ?
ZVA* Station called is responsible for relay or
delivery to all stations in line two (2) or
to stations indicated.
ZVB Varying bias.
ZVB* My time over last compulsory reporting What was your time over last
point was ... and ETA at next compulsory compulsory reporting point,
reporting point is ... and ETA at next compulsory
reporting point ?
ZVE* Security conditions at my termination(s) What are the security
of this channel (or ... channel/circuit conditions of your
designated) are ... termination(s) of this
(1) secured for Restricted; channel (or ... channel/
(2) secured for Confidential; circuit designated) ?
(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 followed 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 The speed of transmission What is your speed of
is ... transmission ?
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** Readability is ... ("I hear you ...");
ZZF* Incorrect.
ZZG* You are correct.
ZZH* Try again.
ZZN* Message is a drill message for ...
(1) beginning operator
(2) advanced operators
(3) operators on watch.
ZZO* Beginning operator.
ZZS** Change freq. to ... ("Go to...");
List derived from a Table of Z-Codes © 1999-2001 by Ralf D.Kloth, Ludwigsburg, DE.
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