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ERA Railway Terminology Collection

Last updated: 12 March 2026

The ERA Railway Terminology Collection gathers terms and abbreviations that are contained in the EU legal framework for railway, technical documents produced by bodies which are engaged in the development of important evolution in the railway system and other relevant glossaries.

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Starting with "C" (756)

ERA Railway Terminology Collection is a consultation tool, developed to support the sharing of information through the actors involved in running the Single European Railway Area (SERA). The responsibility for the correctness, completeness, accuracy, or reliability of the information in ERA RTC lays upon the authors of the definitions, as they derive from reference documents having their own preparation and approval flow. Users cannot call ERA liable for the use they make of the content. Please consider that when the collection is exported (.csv) and then printed or converted, it becomes uncontrolled.
Term Context Document Type Origin document

Critical entity

EU Policy

Directive

Directive (EU) 2022/2557 of the European Parliament and of the Council of 14 December 2022 on the resilience of critical entities and repealing Council Directive 2008/114/EC

Latest release

Critical event (CE) (in the bow-tie):

Freight

Glossary

Handbook of scenarios for assessing major chemical accident risks JRC106029 - Ed. 2017

Critical heat flux at extinguishment (CFE)

International Standard

ISO

ISO 5658-2:2006(en) Reaction to fire tests — Spread of flame — Part 2: Lateral spread on building and transport products in vertical configuration

Critical infrastructure

Infrastructure

Directive

Directive (EU) 2022/2557 of the European Parliament and of the Council of 14 December 2022 on the resilience of critical entities and repealing Council Directive 2008/114/EC

Critical infrastructure

EU Policy

Directive

Directive (EU) 2022/2557 of the European Parliament and of the Council of 14 December 2022 on the resilience of critical entities and repealing Council Directive 2008/114/EC

Latest release

Critical or criticality

International Standard

ISO

ISO 22163:2023(en) Railway applications — Railway quality management system — ISO 9001:2015 and specific requirements for application in the railway sector

Critical path

International Standard

ISO

ISO 22163:2023(en) Railway applications — Railway quality management system — ISO 9001:2015 and specific requirements for application in the railway sector

Critical path

SMS Safety Culture Human and Organisational Factor

ISO

ISO 22163:2023(en) Railway applications — Railway quality management system — ISO 9001:2015 and specific requirements for application in the railway sector

Latest release

Critical temperature

International Relations

Convention

Convention concerning International Carriage by Rail (COTIF) Appendix C – Regulations concerning the International Carriage of Dangerous Goods by Rail (RID)

Criticality

ERTMS

Technical Document

ERTMS/ETCS - Glossary of Terms and Abbreviations - version : 4.0.0 - date 05/07/2023

Criticality safety index (CSI)

International Relations

Convention

Convention concerning International Carriage by Rail (COTIF) Appendix C – Regulations concerning the International Carriage of Dangerous Goods by Rail (RID)

Cronos

EU Policy

EU Technical Document

Technical document from the Publications Office of the European Union - ‘Style guide’ Coordination Interinstitutional Style Guide - version on 19.04.2022

Cross border link

International Relations

Regulation

Regulation (EU) 2021/1153 of the European Parliament and of the Council of 7 July 2021 establishing the Connecting Europe Facility and repealing Regulations (EU) No 1316/2013 and (EU) No 283/2014

Cross section area

Infrastructure

Regulation

Commission Implementing Regulation (EU) 2019/777 of 16 May 2019 on the common specifications for the register of railway infrastructure and repealing Implementing Decision 2014/880/EU

Cross-Acceptance

ERTMS

Technical Document

ERTMS/ETCS - Glossary of Terms and Abbreviations - version : 4.0.0 - date 05/07/2023

Cross-acceptance

RNE Glossary

Glossary

RNE Glossary - NS_CID_Glossary_2025

Cross-border agreement

SERA_EU Transport

Directive

Directive 2012/34/EU of the Parliament and of the Council of 21 November 2012 establishing a single European railway area (recast)

Cross-border interoperability

Interoperability

Regulation

Regulation EU) 2024/903 of the European Parliament and of the Concil of 13 March 2024 laying down measures for a high level of public sector interoperability across the Union.

Cross-border processing

Data Protection

Regulation

Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016 on the protection of natural persons with regard to the processing of personal data and on the free movement of such data, and repealing Directive 95/46/EC

Cross-border project

Infrastructure

Directive

Directive (EU) 2021/1187 of the European Parliament and of the Council of 7 July 2021 on streamlining measures for advancing the realisation of the trans-European transport network (TEN-T)