1. Member States shall require that investment firms comply with the following requirements:

(a) they must keep records and accounts enabling them at any time and without delay to distinguish assets held for one client from assets held for any other client and from their own assets;

(b) they must maintain their records and accounts in a way that ensures their accuracy, and in particular their correspondence to the financial instruments and funds held for clients and that they may be used as an audit trail;

(c) they must conduct, on a regular basis, reconciliations between their internal accounts and records and those of any third parties by whom those assets are held;

(d) they must take the necessary steps to ensure that any client financial instruments deposited with a third party, in accordance with Article 3, are identifiable separately from the financial instruments belonging to the investment firm and from financial instruments belonging to that third party, by means of differently titled accounts on the books of the third party or other equivalent measures that achieve the same level of protection;