This standard: defines the various profiles needed to install, verify and maintain the various structures near the structure gauge; lists the various phenomena to be taken into account to determine the structure gauge; defines a methodology that may be used to calculate the various profiles from these phenomena; lists the rules to determine the distance between the track centres; lists the rules to be complied with when building the platforms; lists the rules to determine the pantograph gauge; lists the formulae needed to calculate the structure gauges in the catalogue. The defined gauge includes the space to be gauged and maintained to allow the running of rolling stock, and the rules for calculation and verification intended for sizing the rolling stock to run on one or several infrastructures without interference risk. This standard defines methodologies to demonstrate gauge compatibility between infrastructure and rolling stock. This standard defines the responsibilities of the following parties: a) for the infrastructure: 1) gauge clearance; 2) maintenance; 3) infrastructure monitoring. b) for the rolling stock: 1) compliance of the operating rolling stock with the gauge concerned; 2) maintenance of this compliance over time. The gauges included in these standards have been developed as part of their application on European railways. Other networks such as regional, local, urban and suburban networks may apply the gauge regulations defined in this standard. They may be required to make use of specific methodologies, particularly where: specific rolling stock is used (for example: underground trains, trams, etc. operating on two rails); use occurs in other ranges of radii; others, etc. The catalogue included in this standard only includes a selection of gauges and is not exhaustive. Each network is free to define the gauges in accordance with their own needs. 2