There are 3 buttons at the bottom right corner of other members' posts.
QUOTE - Opens a reply window with only that particular post "quoted."
'+ - Multi-quote button. Click that when you want to include a particular post in a reply. Once you have selected the posts you wish to reply to, click on the "QUOTE" button in the final post you want to reply to, and a reply window should open with all the selected posts quoted.
Quill (far right button) - Takes you to the bottom of the page, where a "Quick Reply" window is open...designed to be easier than clicking on the orange "Post Reply" button under the final post at the left on each page.
Hope this helps.