Common Q Codes.

The international Q codes are intended to be used to shorten sentences when working with CW. Each code can be used to convey a question, reply, request or statement. When used as a question or request for information, the code will be followed by a question mark.
Q codes are not often used on CB radio, but you may occasionally hear them.

Code:	Meaning
QRK	Readability of signal.
QRL	Busy.
QRM	Man made interference.
QRN	Natural interference such as static.
QRO	Increase power / High power.
QRP	Reduce power / Low power.
QRQ	Send faster / shall I send faster?
QRS	Send slower / shall I send slower?
QRT	Stop transmitting / close down.
QRX	Stand by.
QRZ	Who is calling?
QSA	What is my signal strength? / Your signal strength is...
QSB	Is my signal fading? / your signal is fading.
QSL	Confirm radio contact.
QSO	Contact, communication.
QSY	Shall I change frequency? / Change frequency.
QTH	Location.