Communicating effectively about a technological project involves the use of diagrams. They must be as clear as possible to explain the operating principles.
Each technical field (kinematics, thermodynamics, electrical, electronics, piping, building, etc.) has its own conventions. It is not easy to handle, especially since standardization is not always complete or often remains inaccessible. The site of the Belgian Standardization Office can give you access to standards if your establishment has entered into a consultation agreement (this is the case with UMONS).
Here are some links to find the information you are looking for.
Kinematic links and power transmission components: form SCHL (NBN ISO 3952-1, 3952-2, 3952-3)
Piping and Instrumentation Diagram (P&ID): NBN EN ISO 10628-2, Projectmaterials site
Electrical symbols: IEEE 315 standard