Position
The position key defines when the rule should be invoked. You have three different options: BEFORE, AFTER and INSTEAD. If you do not specify the position it will default to AFTER
Every action that has a BEFORE position will be executed before the action is dispatched. That is super usefull when you want to access the state before it is changed by the target action
Every action that has a INSTEAD position will be executed instead of the target action. The original action will never get dispatched
Every action that has a AFTER position will be executed after of the target action. Here you can access the state after it changed
You can read about the position key in a more detailed documentation: