This standard BS EN 15220:2016 Railway applications. Brake indicators is classified in these ICS categories:
45.060.01 Railway rolling stock in general
This European Standard specifies the requirements for the design, dimensions, performance and testing of single double and multiple brake indicators. It applies to pneumatically and electrically operating brake indicators visible from the outside of the vehicle.
NOTE Brake indicators are for giving information about release and application of the brake.
This European Standard applies to brake indicators on railway vehicles used on the main national networks, urban networks, underground railways, trams and private networks (regional railways, company railways etc.).
This document does not apply to brake indicator for magnetic track brake or eddy current brake.