ESMA have issued a detailed guidance document on the transaction reporting, order record keeping and clock synchronisation rules, which can be found here.An accompanying final report can be found here.
The guidelines elaborate on the different Regulatory Technical Standards already published, numbers 22(annex), 24 (annex) and 25 (annex). In the case of transaction reporting, the guidelines review general principles and scenarios and then examines the blocks of fields in detail. The order record keeping guidance is shorter and also examines principles and field details. Clock synchronisation includes reportable events and time-stamp granularity.
The rules apply to investment firms and venues, which includes energy and commodity market participants that set up regulated entities as a result of the ancillary activity test, or by undertaking other regulated activity.