I have the feeling that some list members may not know how to delete parts of the messages they're referring to. Editing to avoid excessive quoting is quite simple:
1. Find the place in the text where you wish to start deleting
2. Press the left key on your mouse
3. Mark the text you wish to delete
4. Press the delete button in the top right-hand corner of your keyboard.
This can also be done using the shift key and the up and down keys, but if you have a mouse, the procedure outlined above is simple.