PM, Would you like to read the background to your post and does it apply today?
'Maintenance means…the doing of any work (including a modification or repair) on the aircraft that may affect the safety of the aircraft or cause the aircraft to become a danger to person or property…'
'Servicing…means preparing the aircraft for flight, and includes providing the aircraft with fuel and other fluids…but does not include any work that is maintenance.'
Certification for the completion of servicing tasks is not required when preparing the aircraft for flight, unless specifically required as part of an approved system of maintenance.
Certification is required when performing servicing tasks in conjunction with a maintenance activity.
I guess checking engine oil levels is maintenance task then.
SRM