(5)It is necessary to lay down in a regulation a number of uniform obligations to be imposed on market participants regarding certain aspects of the settlement cycle and discipline and to provide a set of common requirements for CSDs operating securities settlement systems. The directly applicable rules of a regulation should ensure that all market operators and CSDs are subject to identical directly applicable obligations, standards and rules. A regulation should increase the safety and efficiency of settlement in the Union by preventing any diverging national rules as a result of the transposition of a directive. A regulation should reduce the regulatory complexity for market operators and CSDs resulting from different national rules and should allow CSDs to provide their services on a cross-border basis without having to comply with different sets of national requirements such as those concerning the authorisation, supervision, organisation or risks of CSDs. A regulation imposing identical requirements on CSDs should also contribute to eliminating competitive distortions.