Why Q signals are three-letter shorthand from the international radio service; QRS means "send more slowly" (with a question mark it asks "shall I send more slowly?"). If the other operator sends QRS, they are telling you your code speed is too fast for them, so drop your words-per-minute until they can copy comfortably. Its opposite is QRQ, meaning send faster.
Watch out QSY is the signal for changing frequency and QRO means increase power, so those choices belong to different Q signals; asking for repeats is QRM-related traffic handling, closest to QSM or "PSE RPT".
QRS: the S stands for Slow. QRQ = Quicker.