This Change Proposal amends the wording of Schedule 5 of the Market Arrangements Code (MAC) to address an area of non-compliance. Schedule 5 contains a requirement that MOSL keep a physical copy of the Central Market Operating System (CMOS) in Escrow so that there is no loss of key market data should CMOS fail. The back-up copy must contain the previous 18 months of CMOS data. The Change Proposal enables MOSL to replace the requirement to have a physical copy with a real time, cloud-based back-up of CMOS that can be accessed should CMOS fail. The Change Proposal will allow MOSL to have a constantly up to date back-up of CMOS and improve speed of access should this be necessary.