>> you can't assign a group number already assigned automatically

> The doc clearly says:

> "There is no particular restriction on the numbering,
> e.g. you can have several groups with the same number in which case
> the last one to match (i.e. the rightmost match) will win."

> There is no mention of an automatic assignment. It says the last one
> will win, so assigning a number which is already used for
> a previous group should work.