Codes are an essential component of any Machine-To-Machine information flow. Codes have been developed over time to facilitate the flow of compressed, standardized values that can be easily validated for correctness to ensure consistent semantics. Many international, national and sectoral agencies create and maintain code lists relevant to their area. If required to be used within an information flow, these code lists will be stored in their own environment and referred to as external code lists.
The project’s purpose is to define the procedures and methodologies for code list usage, validation, management and maintenance. The resulting rules and guidelines will primarily be mandated for all UN/CEFACT deliverables but also applicable to external organisations.

The project will define the procedures, rules and methodologies for the following identified issues. Existing rules, such as those defined in the Core Components Technical Specification, CCTS, should be taken into account and if applicable be respected.
The project should take into account any UN/CEFACT deliverable that apply codes.
The primary target audience is UN/CEFACT Experts developing deliverables using coded representations but guidance to end users should be added when appropriate.

1.	Version compatibility
The ability to use the latest possible version of a code list in association with any version of a message, i.e. decoupling the versioning of code lists from the business message versions

2.	Extending code lists
Evaluate if permanent extensions are possible and desirable

3.	Restricting code lists
Provide rules and methodology for restricting code lists for use within specific context. Users of the UN/CEFACT libraries may identify any subset they wish from a specific code list for their own community requirements. 

4.	Code list validation rules
Provide rules and methodology for how to validate instance documents against an XML Schema or UN/EDIFACT message type in respect to code lists

5.	Temporary codes
Provide rules and methodology for the inclusion of temporary codes that will be replaced by a permanent code at the next UN/CEFACT standardised release.

6.	Externally maintained code lists
Define rules and procedures for referencing code lists maintained by organisations external to UN/CEFACT, e.g. ISO, ICC, W3C.

The deliverables from the project will be:
a)	A User Guide, referring to UN/EDIFACT Syntax Implementation Guidelines and UN/CEFACT Technical Specifications and other specifications, which describes how to use, validate and manage and maintain codes and code lists.
b)	Updates to existing Technical Specifications, if rules and/or guidelines in the new User Guide proposed in point a) contradicts existing rules/guidelines

The resulting updated Technical Specifications described in point b) will be applied for new development. Updates of existing code lists will have to be evaluated on a case-by-case basis.

a)	The User Guide  approved by the Bureau
b)	New versions of existing Technical Specifications approved by the Bureau, if applicable

The project team is open to UN/CEFACT Experts with broad knowledge and experience in the area of code list management and related activities as well as in modelling techniques. Experts are expected to contribute to the work based solely on their expertise and to comply with the UN/CEFACT Code of Conduct and Intellectual Property Rights policy.

India
Japan
Morocco
Spain
Sweden

The geographic focus of the project is global.

Initial contributions will be sourced from existing documentation and standards including:
     • Part 4 United Nations Rules for Electronic Data Interchange for Administration. Commerce and Transport, 
          - Chapter 2.3 UN/EDIFACT Syntax Implementation Guidelines.
          - Chapter 7.8 User Conventions for the Implementation of UNSMs under Amendment (www.unece.org/fileadmin/DAM/trade/untdid/texts/d423.htm)
     • UN/CEFACT XML Naming and Design Rules for CCTS 2.01 Version 2.1 dated 27 May 2014
     • Core Components Business Document Assembly Technical Specification, CCBDA, version 1.0
     • ISO 20625 Electronic data interchange for administration, commerce and transport (UN/EDIFACT) -- Rules for generation of XML scheme files (XSD) on the basis of EDI(FACT) implementation guidelines.
     • Best practice from external organisations

Participants in the project shall provide resources for their own participation.
The continued existence and functioning of the project team shall not require any additional resources from the UN/ECE secretariat other than: 
     • Establishing and maintaining the project team's Web site pages with appropriate links, document download facilities, and items of interest

Project Leader:  Rolf Wessel
Lead Editor: Gerhard Heemskerk