ISO 20022 messages aim at being global and catering for the business needs of all communities. In general, a particular community of users will not need all of the features defined in the global message.
A 'variant' is a restricted version of a global message that fits the needs of a particular community. Communities of users are invited to define their variants and have them published in the Catalogue of ISO 20022 messages together with the global messages.
To ensure that the variants are all expressed in a standard way, communities are invited to use the Master Message Template provided for each ISO 20022 message in the Full catalogue (via the hyperlink in column "T or P").
The Master Message Template is an 'intelligent' spreadsheet which contains all the elements of the global ISO 20022 message and helps communities to 'restrict' the message to the subset that is required to address their specific needs, while remaining in strict compliance with the original ISO 20022 message.
For example, optional items can be removed or made mandatory, choices can be removed to keep no or fewer options, internal code lists can be reduced to the subset of codes that will actually be used, size of text fields can be reduced. A guide "How to customise a Master Message Template" is available.
Customised Message Templates can be submitted to the Registration Authority for publication. Please identify clearly the name of the user community and a link or e-mail address where more information, such as the full implementation guidelines, can be obtained.