* By default, the most recent message is selected and its references are visible.
When a new message is posted, previous arrows will not be displayed.
Keyboard Shortcut:
You can also make a reference by only using the keyboard.
1. Press Crtl-Space. A scrollable pop-up window (figure 3)
containing all messages
will appear below the text-box (most recent contributions will be listed first).
2. Use up and down arrow buttons to move the blue selection area over the list of
messages. When the target message is highlighted press Space to select it. You
can select multiple messages in this way. Press Return when you are done with
selecting messages. (Now you should see a blue line with an arrow pointing from
the text field to the message(s) you selected.)
3. Enter your message in the text field.
4. Press Return to post your message. 
Figure 3