(1) If the obligee notifies the obligor of the claim having been assigned, they must allow the notified assignment to be asserted against them in relation to the obligor, even if it does not occur or is not effective. It is equivalent to the notification if the obligee has issued a document relating to the assignment to the new obligee named in the document and the latter presents it to the obligor.
(2) The notification may be retracted only with the approval of the person who has been named as the new obligee.