If SAP E-Mobility knows the charging station model:

Each of the system-provided parameters is marked as Added by System in the Source column.
If you modify the Active Value of a system-provided parameter, the Source is set to System Value Overwritten.
You can see what was the initial system value in the Recommended Value column.

If the charging station model is unknown, or if you've modified the connectors, each OCPP parameter retrieved with the Download Configuration button is set to Added by User.

If you add an OCPP parameter manually, it is also set to Added by User.