Amendment Processes to WIS Manuals and Guides

The rules and procedures for amending the WIS manuals and WIS Guides are described in the Manual on Codes under the General Provisions chapter:  numbers 13 - 17 and in the General Provisions Appendix. This page summarises the options using new organisational terminology introduced by the WMO reform of 2019. The WMO experts on the SC-IMT teams are responsible for proposing, documenting, and testing the amendments.

How to Propose an Amendment

There are multiple ways to introduce changes to WMO publication. Below are the most common options. 

Option A:

Option B: 

  •      If available, submit a proposal in GitHub issues to the relevant repository.

Option C: 

  •  Contact a member of the relevant team. 

Option D: 

  • Send an email to

The task team will then review the request and introduce the change(s) with the appropriate amendment process.

Amendment Procedures

There are 3 procedures:

  1. simple (fast-track) procedure
  2. standard procedure
  3. complex procedure 

1. Fast Track Procedure

The fastest method to amending the manuals is by fast-track. This procedure occurs twice a year and the new amendments are implemented every May and November.  It is not appropriate for major revisions to the structure, major revisions of subject matter or introduction of new volumes.

This procedure shall only be used for amendments to the technical specifications in the following WIS manuals and guides.2

  • Manual on the WMO Information System WMO-No. 1060
    • Appendix A, Appendix C Part 2 section 3 (Data Dictionary) 
  • Guide to the WMO Information System WMO–No. 1061
    • Part V (Metadata guidance), Annex D (Training and Learning guide)
  • Manual on the Global Telecommunications System WMO-No. 386
    • Attachment I-1 (Arrangements for the collection of Ships weather reports and oceanographic reports (BATHY/TESAC)), Attachment I-2 (Configuration of the Main Telecommunications Network), Attachment II-5 (Data Designators T1T2A1A2ii in abbreviated headings)
  • Guide to Information Technology Security WMO-No. 1115
    • Whole document
  • Guide to Virtual Private Networks (VPN) via the internet between GTS centres WMO-No. 1116
    • Whole document 
  • Manual on Codes, Volumes I.2 and I.3 WMO-No. 306
    • Whole document
  • Manual on the WMO Integrated Global Observing System WMO-No. 1160
    • Appendix 2.4 (The WIGOS metadata standard) 


  1. Requirements: Proposals for amendments are gathered year-round and documented in GitHub
  2. Draft Recommendation: The Expert Team prioritizes, proposes solutions, and validates amendments.
  3. Approval: Chair of the SC-IMT.
  4. Review: Summary of amendments are submitted to focal points with two months to review.
  5. Endorsement: President of INFCOM in consultation with SERCOM. 
  6. Adoption: President of WMO on behalf of the Executive Council. 
  7. Publication: Amendments are posted to WMO websites. The manuals and guides are translated and republished annually. 

Fast Track Schedules 

The exact target dates will vary every year. 

Fast Track 1

  • Feb: Submit draft amendments to National Focal Points for consultation.
  • April: Submit draft amendments for endorsement and adoption. 
  • May: Amendments are published and considered operational.

Fast Track 2

  • July: Submit draft amendments to National Focal Points for consultation.
  • Sept: Submit draft amendments for endorsement and adoption.
  • November: Amendments are published and considered operational

2. Standard Procedure

This procedure "shall be used for changes that have an operational impact on those Members who do not wish to exploit the change, but that have only minor financial impact"and for adoption between [CBS] sessions. 


  1. Requirements: Proposals are documented year-round.
  2. Draft Recommendation: The expert team develops the draft recommendation.
  3. Endorsement: Approved by Chair of SC-IMT and President of INFCOM in consultation with SERCOM. 
  4. Review and Adoption: The proposal is circulated to Members with two months to provide comments. If there is no agreement, then the draft amendments follow the complex procedure instead. 
  5. Notification: The Executive Council is notified
  6. Publication: Posted to WMO websites and published. 

3. Complex Procedure

This procedure "shall be used for changes for which the simple (fast-track) procedure or standard .... procedure cannot be applied"1, has a financial impact and for adoption during INFCOM session.


  1. Requirements: Proposals are documented year-round. 
  2. Draft Recommendation: The Expert Team drafts the recommendation. 
  3. Endorsement: Chair of SC-IMT and other affected Standing Committee Chairs of INFCOM and SERCOM as needed. Send to INFCOM 45 days before the session. 
  4. Endorsement during INFCOM Session: Approve and recommend to Executive Council.
  5. Adoption: Executive Council.
  6. Publication: Posted to WMO websites and published. 


1. Manual on Codes Vol I.2 (2019), General Provisions chapter

Last Update: 12 Nov 2020