EBU Single Rulebook Q&A 25 June 2019 2019_4805 Large Exposures treatment of Nostro Accounts used for correspondent banking

Do Nostro Accounts used for correspondent banking activities always meet the exclusion criteria specified under Article 390(6) CRR?To the extent that a low amount of exposure is always left in the same accounts, as a buffer to avoid going overdrawn as a result of the correspondent banking activity, would this be eligible for the exclusions as well? If yes, under which circumstances?