Good points, CK.
However, let's consider harai goshi. My question could be 'what angles can I attack from?', 'What grips should I use?', 'What set up attacks can I use?', 'What is the difference between harai goshi and ashi guruma?', 'When can I counter with harai goshi?', 'How can I defend against harai goshi attacks using grips, movement, kazushi, footwork or some other technique?', 'How was it invented?', 'What does the name really mean?'.
So under the classification 'koshi waza', we have the potential ask about all manner of background, attack, defence, combinations, counters and situational guidance on harai goshi.