How do I activate/unlock the child lock for model RC, MC, RS, MS?

RC/MC-Model :
The Child Lock feature locks the buttons to prevent unintended operation, especially by children. If the Child Lock is set to 'On'(Menu P010), to operate the mower it is required to first press one of the operating mode buttons and then press the "OK"-button to confirm.

RS/MS-Model:
The Child Lock feature locks the buttons to prevent unintended operation, especially by children. To turn this feature on, set Child Lock to 'On' (under the Mower Settings menu). When the Child Lock is turned On, Keys Locked is displayed.

To temporarily release Keys Locked :

Press  then 

* The keys will re-lock after 30 min, without user intervention.