Not with standing the provisions of UCP 600 if we give notice of refusal of the documents presented under this credit we shall however retain the right to accept a waiver of discrepancies from the applicant and, subject to such waiver being acceptable to us, to release documents against the waiver without reference to the presenter, provided that no written instructions to the contrary have been received by us from the presenter before the release of documents. Any such release prior the receipt of contrary instructions shall not constitute a failure on our part to hold the documents at the presenter’s risk and disposal and we will have no liability to the presenter in respect of any such release.信用證里的這些是什么意思?