Auxiliary letter groups or numbers are also used to help define the information that is need or passed with certain Q Code three-letter groups. The International Q Code can be arranged in three types of code groups according to the second letter in the three-letter Q Code.

The Q Code comprises :

• General Codes, second letter of which is R, S, T or U. (Some used by Hams).
• Maritime Service Codes, second letter of which is O, P or Q.
• Aeronautical Codes, second letter of which is A, B, C, D, E, F, G, H, I, J, K, L, M or N.

Some common Q-Codes used by Amateur Radio Operators are:

QRG Will you indicate my exact frequency in kilocycles? Your frequency is ... kc.

QRH Does my frequency vary? Your frequency varies.

QRI How is the tone of my transmission? The tone of your transmission is ...

• 1. Good.
• 2. Variable.
• 3. Bad.

QRJ Are you receiving me badly? Are my signals weak? I cannot receive you. Your signals are too weak.

QRK What is the legibility of my signals (1 to 5)? The legibility of your signals is ... (1 to 5).

QRL Are you busy? I am busy (or busy with....). Please do not interfere.

QRM Are you being interfered with? I am being interfered with.

QRN Are you troubled by static? I am troubled by static.

QRO Must I increase power? Increase power.

QRP Must I decrease power? Decrease power.

QRQ Must I send faster? Send faster ... (words per min.).

QRS Must I send more slowly? Transmit more slowly ... (w.p.m.).

QRT Must I stop transmission? Stop transmission.

QRU Have you anything for me? I have nothing for you.

QRV Are you ready? I am ready.

QRW Must I advise ... that you are calling him on ... kc? Please advise ... that I am calling him on ... kc.

QRX When will you call again? I will call you again at ... hours (on ... kc.).

QRZ By whom am I being called? You are being called by ...

QSA What is the strength of my signals (1 to 5)? The strength of your signals is ... (1 to 5).

QSB Does the strength of my signals vary? The strength of your signals varies.

QSD Is my keying correct? Are my signals distinct? Your keying is incorrect; your signals are bad.

QSG Must I transmit ... telegrams (or one telegram) at a time?  Transmit ... telegrams (or one telegram) at a time.

QSK Shall I continue the transmission of all my traffic? I can hear you between my signals. Continue: I shall interrupt you if necessary.

QSL Can you acknowledge receipt? I am acknowledging receipt.

QSM Shall I repeat the last telegram I sent you? Repeat the last telegram you sent me.

QSO Can you communicate with ... directly (or through...)? I can communicate with ... direct (or through...).

QSP Will you relay to ...? I will relay to ... free of charge.

QSV Shall I send a series of VVV....? Send a series of VVV.

QSX Will you listen for ... (call sign) on ... kcs? I am listening for ... on ... kcs.

QSY Shall I change to ... kilocycles without changing the type of wave? Change to ... kc. without changing type of wave.

QSZ Shall I send each word or group twice? Send each word or group twice.

QTA Shall I cancel nr ... as if it had not been sent? Cancel nr... as if it had not been sent.

QTB Do you agree with my word count? I do not agree with your word count; I shall repeat the first letter of each word and the first figure of each number.

QTC How many telegrams have you to send? I have ... telegrams for you or for ....

QTH What is your position (location)? My position (location) is ....

QTR What is the exact time? The exact time is ....