ButtonMapping and xorg.conf

[John-Scott Atlakson]

I've been wrestling with example xorg.conf hacks I've seen on various 
distro forums to get all the buttons working on my Intellimouse Explorer 
2.0 USB w/tilt wheel working. I'm assuming that since this is the file I 
supposed to hack, that this is the correct place to ask about it. 
Anyway, using xev, I get the following  button numbers:
1=left click
2=wheel click
3=right click
4=wheel scroll up
5=wheel scroll down
8=browse forward
9=browse backward (or at least that's what these two buttons do by 
default without any driver installation in a certain proprietary OS I've 
used)

The tilt wheel does not generate any event when clicking side to side (I 
can live without it, but would rather not. Any ideas?). Here are my 
current xorg.conf settings for the mouse (I changed "Buttons" to "9" as 
that seemed intuitive if 'browse backward'=9, but I'm pretty sure 
everything else is default):

Section "InputDevice"
    Identifier     "Configured Mouse"
    Driver         "mouse"
    Option         "CorePointer"
    Option         "Device" "/dev/input/mice"
    Option         "Protocol" "ExplorerPS/2"
    Option       "Buttons" "9"
    Option         "ZAxisMapping" "4 5"
    Option         "Emulate3Buttons" "true"
EndSection

I've looked at a lot of forum posts which show an "Option" 
"ButtonMapping" followed by a variety of number sequences and I 
understand that this allows you to map physical buttons to 'logical' 
buttons. However, after much searching, I can't seem to find out any 
helpful documentation about the 'logical' button order, so I'm left 
blindly reordering physical button numbers. Now that I think about it, 
are the results of xev telling me physical or logical button numbers? 
Where can I find this information? Thanks in advance for pointing me in 
the right direction.

Cheers,
John-Scott Atlakson