Implemented as a list option:

Default

123.45

123,45

(The list should also display group separator, but for some reason the default number format pattern is set to be ###0.#######... so no group separation occurs.  And, this pattern is hard-coded.)

This is a cleverly coward way out of the group separator problem :-)

This option is effectively only for the decimal separator, as the default numeric pattern does not define a group separator).

see also

http://en.wikipedia.org/wiki/Decimal_separator

1 234 567,89

1.234.567'89

1.234.567,89

123,4567.89

We should label the option "Decimal Separator" and not "Number Format"

renamed.