Fibre optic cleaning techniques are based on the removal of types of dust or oily matter. Single soils are relatively easy to remove compared with ‘combination soils’ that might be dust, combined with human body oil or hand lotion. Understanding the inter-dynamic of location of debris and its physical type is critical to removal. As speeds and capacities increase, and as deployments proliferate, there is a need to consider not only future, but also, heritage installations. Designers, installers and trainers face updates and backdates.