What do Qs mean in keyboarding textbook?

In keyboarding textbooks, "Qs" typically refers to the "quarter shift" key on a keyboard. This key, also known as the "half shift" key, "2-key shift" or "top shift" key, is found on some older typewriter-style keyboards and is usually located on the left side of the upper row of keys, above the "A" and "Z" keys.

The purpose of the quarter shift key is to shift the position of the keys on the keyboard temporarily, allowing typists to input characters that are not readily available on the standard letter keys. When the quarter shift key is pressed, it typically shifts the characters associated with the number keys (1-9) as well as the characters associated with the top row of letter keys (Q-P) by one position to the right.

For example, if you press the quarter shift key and then press the "1" key, instead of typing the digit "1," you will type the exclamation mark (!) character. Similarly, pressing the quarter shift key and then pressing the "Q" key will type the at symbol (@) character.

The quarter shift key is a useful feature for typists who need to input special characters or symbols quickly and efficiently, but it is not as commonly used on modern keyboards as it was in the past.