Since I remapped XButton1 and XButton2 to ctrl+shift+tab and ctrl+tab I wanted to set the right mouse button + XButton1/2 combos as forward&backward.
It works, but I don't have right click now...
I tried writing it as {RButton&XButton1}, needless to say that didn't help, but back/forward still works.
XButton1::Send ^+{Tab}
XButton2::Send ^{Tab}
RButton&XButton1::Send !{Left}
RButton&XButton2::Send !{Right}
I expect the right mouse button to work still as it is intended.