(15)To ensure a sufficient degree of certainty that the UCITS is indeed the owner of the assets, the depositary should make sure it receives all information it deems necessary to be satisfied that the UCITS holds the ownership right over the asset. That information could be a copy of an official document evidencing that the UCITS is the owner of the asset or any formal and reliable evidence that the depositary considers appropriate. If necessary, the depositary should request additional evidence from the UCITS or as the case may be from a third party.