[eluser]xwero[/eluser]
Oh it actually works, extending the rules
Great, maybe we should have some repository where we can add rules CI doesn't include.
There are some manipulated validation classes on the forum but then it's more difficult to update CI so i think extending classes is a good method.
To futureproof this you should make a language file and include it in the class so that the CI validation class and it's dependend files are untouched.