The International Q-Code

History, operating guide, and complete amateur radio reference

The Q-code is a family of compact operating groups whose members normally contain three letters and begin with Q. It was developed for radiotelegraphy so operators could exchange recurring questions, answers, instructions, and reports with fewer characters and less dependence on a shared spoken language. The legacy reference rebuilt here also notes that the Q initial helps distinguish these groups from ordinary station call signs.^[1]

In radiotelegraphy, a question mark changes a Q group into a question. Without the question mark, the same group usually functions as an answer, statement, or instruction. The current ITU maritime recommendation specifies RQ—spoken as “Romeo Quebec”—for the equivalent question form in radiotelephony, although radio amateurs commonly ask the meaning in ordinary speech. Q-codes can be completed with call signs, place names, times, frequencies, numbers, and other data.^[2] The 1912 international service regulations already demonstrated the question-mark convention with worked examples.^[3]

Although the system arose in the Morse era, Q-codes remain part of amateur CW and voice practice. The ITU’s 2026 amateur-service handbook still describes a two-way contact as a QSO and points readers to Recommendation ITU-R M.1172.^[7]

Q-Codes at a Glance

ITU Operating Rules That Matter

• A question mark follows the Q group in radiotelegraphy; RQ performs that role in formal radiotelephony.
• The letters C and NO may add affirmative and negative senses to certain groups.
• Call signs, places, figures, frequencies, times, and other details may complete a meaning.
• Where a group has numbered alternatives, the selected number follows the abbreviation.
• Times are Coordinated Universal Time unless the exchange says otherwise.
• An asterisk in ITU-R M.1172 marks a meaning similar to one in the International Code of Signals.

flowchart TD
    A[Receive a Q group] --> B{Is it followed by a question mark or RQ?}
    B -- Yes --> C[Read it as a request for information or action]
    B -- No --> D[Read it as an answer, statement, or instruction]
    C --> E{Are call signs, numbers, times, or places attached?}
    D --> E
    E -- Yes --> F[Apply the added details in the transmitted order]
    E -- No --> G[Use the group's basic meaning]
    F --> H[Respond or act]
    G --> H

History of the Q-Codes

Early Development Before International Adoption

Wireless operators in the first decade of the twentieth century worked with slow manual Morse, unstable signals, heavy static, interference, and crews who did not always share a language. A short standardized group could replace a complete operational sentence and reduce opportunities for error. The Q-code system is commonly traced to a British Post Office list used around 1909, although surviving secondary accounts differ in how they count and describe the earliest groups.^[9]

London, 1912: An International Operating Language

The International Radiotelegraph Conference met in London from 4 June through 5 July 1912. It revised the convention and service regulations and emphasized intercommunication and safety at sea.^[4] The resulting detailed regulations included a multi-page “List of Abbreviations to be used in Radiotelegraph Transmissions,” with Q groups for station identity, distance, bearings, destination, reception quality, interference, atmospheric noise, power, speed, readiness, traffic, and other recurring needs.^[3]

The 1912 regulations also established the core grammar that still makes the system easy to learn: add a question mark to ask the question; omit it to give the associated answer or advice. The regulations were published in 1913 and came into force on 1 July 1913.^[3]

The Interwar Regulatory Framework

At Washington in 1927, administrations revised the International Radiotelegraph Convention and the general and additional radio regulations, established a table allocating frequencies among services, and created the International Radio Technical Consultative Committee, later known as the CCIR.^[5] These broader international mechanisms gave operating signals such as Q-codes a stable regulatory environment in which to evolve across services.

Atlantic City, 1947

The 1947 Atlantic City conferences revised the global radio framework, changed frequency allocations, created the International Frequency Registration Board, and produced new Radio Regulations and Additional Radio Regulations.^[6] Q-code assignments were increasingly organized by service, helping explain why amateur operators use only a practical subset while maritime, aeronautical, and other services have additional groups.

Modern ITU Standardization and Amateur Survival

Recommendation ITU-R M.1172, issued in 1995, codifies miscellaneous abbreviations and signals for maritime-mobile radio communication. Its Q-code annex runs from QOA through QUZ, reserving QOA through QQZ for the maritime mobile service and documenting the question, answer, and advice forms used for the later groups.^[2]

Amateur radio retained the groups that solve everyday station problems: frequency, readability, interference, static, power, speed, availability, acknowledgement, contact, location, and time. Many became ordinary radio nouns or verbs—operators make a QSO, send a QSL, operate QRP, encounter QRM, or QSY to a clear frequency. ARRL’s historical overview likewise describes the long transition from formal operating signals to informal amateur vocabulary.^[8]

flowchart TD
    A[About 1909: early British operating shorthand] --> B[1912: London conference adopts international abbreviations]
    B --> C[1 July 1913: revised service regulations take effect]
    C --> D[1927: Washington revises regulations and creates CCIR]
    D --> E[1947: Atlantic City revises the world radio framework]
    E --> F[1995: ITU-R M.1172 standardizes maritime Q-code use]
    F --> G[Today: a practical subset remains active in amateur CW and voice]

How to Use Q-Codes on the Air

Question and Answer Pairs

A Q-code is most useful when both operators understand its paired forms. For example, QRG? asks for an exact frequency, while QRG 14.060 MHz supplies it. QRV? asks whether the other operator is ready, while QRV states readiness. The surrounding exchange determines whether a bare group is descriptive, advisory, or imperative.

A Typical Amateur Contact

flowchart TD
    A[Call or answer a station] --> B[Exchange call signs]
    B --> C[Check frequency, readability, strength, and interference]
    C --> D[Exchange names, locations, reports, and other information]
    D --> E{Is a relay or frequency change needed?}
    E -- Relay --> F[Use QSP or QSO relay wording]
    E -- Change frequency --> G[Use QSY with the destination frequency]
    E -- No --> H[Continue the contact]
    F --> H
    G --> H
    H --> I[Acknowledge important information with QSL]
    I --> J[Close the QSO or go QRT]

Good Operating Practice

• Use only as many Q-codes as improve clarity; plain language is often better on voice.
• Do not assume an informal amateur meaning is identical to the formal ITU meaning.
• Attach the needed number, time, frequency, place, or call sign rather than forcing the other operator to guess.
• On CW, preserve the question mark when asking; without it, the same group may be read as a statement or command.
• When handling formal traffic, emergency work, maritime communication, or examinations, consult the governing current publication rather than an informal list.

Amateur Radio International Q-Code

Radio amateurs rely on a subset of the larger international system. The exact list emphasized in training or examination material can vary by administration, but the following table preserves every formal amateur entry shown on the legacy page, with newly written wording and the paired question and answer forms.^[1]

Amateur Radio Informal Q-Code

In everyday amateur conversation, many groups have become substitutes for single words or short phrases. These informal meanings are convenient, but they are not always identical to the formal question-and-answer definitions. The table preserves all informal entries shown on the legacy page, including the four-letter extension QRSS.^[1]

Reporting Scales and Graphs

Common Numerical Scales

xychart-beta
    title "Maximum value of common Q-code reporting scales"
    x-axis ["QRI tone", "QRK intelligibility", "QSA strength", "QRM interference", "QRN static"]
    y-axis "Maximum scale value" 0 --> 5
    bar [3, 5, 5, 5, 5]

Distribution of the Legacy Full-List Rows

The rebuilt QRA–QUZ table contains 103 displayed rows: 26 QR rows, 25 QS rows, 27 QT rows, and 25 QU rows. The QT count is 27 because the source page displays QTI twice with two different wordings; both rows are retained and explained in the verification notes.

pie showData
    title Legacy QRA–QUZ reference rows by prefix
    "QR" : 26
    "QS" : 25
    "QT, including duplicated QTI" : 27
    "QU" : 25

Full International Q-Code Reference: QRA–QUZ

The following is the broader list carried by the legacy page. Most of these groups relate to maritime traffic, direction finding, rescue, weather, navigation, or formal message handling and are rarely needed in ordinary amateur contacts. The source page shows only the question or statement side for this larger table; that structure is retained here, with the wording independently rewritten.^[1]

This is not the whole universe of Q groups. Other ranges have been assigned or used in maritime and aeronautical services. For current formal maritime meanings and their complete answer/advice forms, Recommendation ITU-R M.1172 is the controlling reference used for verification here.^[2]

Verification and Editorial Notes

Preserved Legacy Differences

References

1. The international Q-code / Amateur radio informal Q-code. Giangrandi.org. Legacy page created October 1999 and last updated October 2013. Accessed 10 July 2026. https://www.giangrandi.org/electronics/radio/qcode.shtml
2. Recommendation ITU-R M.1172: Miscellaneous abbreviations and signals to be used for radiocommunications in the maritime mobile service. International Telecommunication Union. 1995. Accessed 10 July 2026. https://www.itu.int/rec/R-REC-M.1172/en
3. Detailed Service Regulations appended to the International Radiotelegraph Convention (London, 1912). His Majesty’s Stationery Office; digital scan by the ITU Library and Archives Service. Published 1913. Accessed 10 July 2026. https://search.itu.int/history/HistoryDigitalCollectionDocLibrary/1.3.48.en.100.pdf
4. International Radiotelegraph Conference (London, 1912). International Telecommunication Union, History of ITU Portal. Conference held 4 June–5 July 1912. Accessed 10 July 2026. https://www.itu.int/en/history/Pages/RadioConferences.aspx?conf=4.37
5. International Radiotelegraph Conference (Washington, 1927). International Telecommunication Union, History of ITU Portal. Conference held 4 October–25 November 1927. Accessed 10 July 2026. https://www.itu.int/en/history/Pages/RadioConferences.aspx?conf=4.39
6. International Radio Conference (Atlantic City, 1947). International Telecommunication Union, History of ITU Portal. Conference held 16 May–2 October 1947. Accessed 10 July 2026. https://www.itu.int/en/history/Pages/RadioConferences.aspx?conf=4.62
7. Handbook on Amateur and amateur-satellite services. International Telecommunication Union. 2026 edition. Accessed 10 July 2026. https://www.itu.int/dms_pub/itu-r/opb/hdb/R-HDB-52-2026-PDF-E.pdf
8. Ham Radio History. American Radio Relay League. Historical overview of amateur operating language and Q-signals. Accessed 10 July 2026. https://www.arrl.org/ham-radio-history
9. Q-codes. Crypto Museum. Historical overview; used cautiously for the commonly cited pre-1912 origin. Accessed 10 July 2026. https://www.cryptomuseum.com/ref/qcodes/