Master Locksmiths Access Key (MLAK) are a system key for disability toilets  Key can be arranged to be used for access to disability toilets 

The MLAK system is an MLAA initiative that allows people with a disability access to dedicated public facilities, including facilities in National Parks and many Council municipalities, elevators at railway stations, the new Changing Places facilities throughout Australia, disabled toilets that are locked, and the Liberty Swing. It was launched back in 1994 as a joint venture between Pittwater Council, ACROD and the MLAA, before being implemented Nationally.

People with a disability are able to purchase an MLAK which will open all toilets, playground equipment and other facilities fitted with a lock that uses the special MLAK cylinder.

See link for the brochure below:

master locksmiths access key