A message set is identified by the name of the message set folder in the message set.
When you need to refer to a message set from a message flow (for example, when setting the Message Set property of an input node), use the message set name.
A message set also has a 13-character identifier that is guaranteed to be unique. You can use this identifier, instead of the message set name, to refer to a message set, but only if you are using the MRM or IDOC domains. Other domains do not recognize the identifier.
A message set also has an alias. An alias can only be used with MRM multipart messages.