From a Ubuntu bug:
https://bugs.edge.launchpad.net/ubuntu/+source/xkeyboard-config/+bug/188342

[Problem]
It sounds like there is no good solution for handling KPDL, but we're getting some pushback from french users who would like the default switched to be KP_Decimal rather than period on fr keyboards.

Is this something that would be reasonable to consider changing?

[Original Report]
In Ubuntu 7.10, xserver-xorg-input-kbd_1.2.0-1+1.2.1ubuntu1 with the following Xorg.conf settings:

Section "InputDevice"
        Identifier "Generic Keyboard"
        Driver "kbd"
        Option "CoreKeyboard"
        Option "XkbRules" "xorg"
        Option "XkbModel" "pc105"
        Option "XkbLayout" "fr"
        Option "XkbVariant" "oss"
EndSection

Got:
$ xmodmap -pke | grep 'keycode *91'
keycode 91 = KP_Delete period comma U202F comma U202F

Expected:
$ xmodmap -pke | grep 'keycode *91'
keycode 91 = KP_Delete KP_Decimal comma U202F comma U202F

This issue is a MAJOR usability issue in OpenOffice.org Calc, as in the current state Calc is unusable to enter decimal numbers quickly.
This is a major blocker for migration of Windows/Excel users to Ubuntu/OpenOffice.org. See bug #188331.

(Another reporter adds "And yes indeed, "French uses a comma as decimal separator, but keyboards are labeled with a period". Neverless all french users expect that their numpad '.' gives a comma. And that's what happens in the "Windows" world. So give it to us, please ;-)" )

The file to fix is probably /usr/share/X11/xkb/symbols/fr, lines 389 to 391:

< // French uses a comma as decimal separator, but keyboards are labeled with a period
< // Will take effect when KP_Decimal is mapped to the locale decimal separator
< key <KPDL> { [ KP_Delete, period, KP_Delete, KP_Decimal ] };

> key <KPDL> { [ KP_Delete, KP_Decimal, KP_Delete, KP_Decimal ] };