The commonly used standard for CCTV reporting is detailed in the Manual of Sewer Condition Classification Manuals (MSCC). There is a difference between drains and sewers, but MSCC allows for this by using a revised subset for domestic and light commercial drains.
These manuals are produced by the Water Research Centre, who also produce a manual called the Drainage Repair Book (DRB). This not only describes repair philosophy but also discusses when a drain might require repair based on its serviceability.
Viewline works to both these standards, often using automation, meaning that drainage contractors are guided to standard-compliant reports and end users receive reports that should also be standard-compliant.