As part of the SDI Standard Operating Procedures data gets harmonized for viewing and filtering purposes.
Data harmonization uses expert/scientist input to map existing metadata (parameter names, method/device, and unit) to a standard vocabulary (esp. NERC). This process is called Mapping.
A documentation of the Status Quo of the Mapping infrastructure, including recent database dumps, some statistics and a presentation explaining the underlying principle can be found in the DAM space → https://spaces.awi.de/x/CyBGF.