Update January 2020: SSMDS is no longer being developed. Instead we refer to GBFS.
SSMDS is a project of the Swiss Federal Office of Energy (SFOE). The aim is to create a data exchange standard for shared mobility data such as bikesharing or carsharing. The providers of shared mobility are using this standard to transmit their data to the SFOE. With this data, the SFOE generates an overall view of the shared mobility offers in Switzerland.
The specification is found here.