[Koha] Classification Scheme Questions

[Nicole Engard]

I have 2 questions about classification sources:

1 - How does the classification source work in terms of sorting call
numbers when you have multiple class schemes (like LC and SUDOC)?
2 - what is the purpose of filing rules? all i can add is a title and
code…do they need some sort of code behind them to work? how do I know
what the filing rules actually are for the default ones?

Basically - I have no clue how to document the Classification Sources :)

Thanks
Nicole