Question 5.1.2 Data Field (2) Message ID

Shall the version number - that is part of the ‘Message ID’ - be incremented with any update to the UMM thread? If so, will the increment of version number always result in a new UMM published to RSS/Atom feed?

Answer: As explained in the MoP Annex VII each ‘Message ID’ includes 29 characters in total and consists of 3 parts:

• ‘UMM thread ID’ - 25 characters
• One underscore (‘_’)
• ‘Version number’ - 3 characters

Underscores (‘_’) should not be used within the 25 characters of the UMM thread and also it shall not be possible to submit a message with a ‘Message ID’ of less than 29 characters in total.

Any change in the UMM results in a change on the ‘Message ID’. If the same UMM thread is considered, the change will impact the last part of the ID which is the UMM ‘Version number’. It is the responsibility of the reporting parties to put in place appropriate arrangements ensuring proper sequencing of this number.