City of Sydney Relationships Declaration
Other institutions such as the Registry of Births Deaths and Marriages no longer accepts an Australian Marriage Certificate as a form of ID – this creates an equal situation for both opposite sex and same sex couples as both are not allowed to present their relationship certificates as a form of ID.
EIDAS
eIDAS has as minimum identity concept, the name and birth date. But in order to access more sensitive information, some kind of certification is needed that identity numbers issued by two countries refer to the same person.