The enforcement regulation is still in the hands of individual nations. If a country has issued guidelines on enforcement beginning July 1, then that date will apply to exporters within that nation. For those nations still working to clarify details on the regulation, as SOLAS signatories, the memorandum allows for additional time.
The October 1 date is noted as the closure date on such flexibility. At that time, it can be interpreted that full enforcement will begin as specified in the original regulation. It is also important to note that if a country has not published national legislation on the subject, the SOLAS amendment is still in force.