An ability's order string

What's an ability's order string ? I know for normal moves like attack or stop, its order string is just the same spelling. But it doesn't apply for abilities. I've tried inputting the exact spelling like 'mana burn' or 'avator' and it doesn't work. Nor do its codename..... any ideas ?

the correct strings are manaburn and avatar. None of the ability strings have a space. You can see the ability strings if you look at the ability in the object editor, and check where it says ... I don't remember what the field is called but it should be easy to spot, it has something to do with strings and its default value is usually the ability's name in lowercase without space.

I got it, there's a field stating its order string. thank you