In the UK, a TR19 "paper" or certificate is used to prove a ventilation system has been cleaned to BESA (Building Engineering Services Association) standards. Key Sections for a TR19 Report
A detailed plan or schematic of the ductwork and extraction system. Download File SuperHuman_(UK)-Reflections-(TR19...
If you tell me more about your specific goal, I can provide a more targeted outcome: In the UK, a TR19 "paper" or certificate