Decision Modding Question

[Zeisix]

So to activate the 'single_heir_succession_law_youngest' within a decision, you need the code
primary_title = {
change_succession_law = succession_ultimogeniture
}

But how is this working as there is no law called 'succession ultimogeniture'?

If I had a custom law called 'my_custom_succession_law'.
primary_title = {
change_succession_law = my_custom_succession_law
}
wouldn't work?

I'd need to use the 'add_realm_law_skip_effects'