The RemoveCharacterFromPostCode order rule action can remove specific characters from the PostCode field on an order. For the Param field, you enter the character you want to remove on the order.
Example - Remove hyphen from postcode
You want to remove any hyphens within the postcode field on the order.
Action: RemoveCharacterFromPostCode
Param: -
OrderRuleConditions: (Optional)
Then, if an order imports with a hyphen anywhere in the PostCode field, it will be removed.