Reference Topics > View options > Message view options - system architecture diagram
  
Message view options - system architecture diagram
Show Message Numbering—specifies that message numbering is shown.
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• If you hide message numbering for new messages and then add a new message, the new message will not be allocated a message number.
• The Sequence Number is set on the Options tab of a message's instance Property Pages.
If you opened the View Options by right-clicking the diagram background, the check boxes you select set the default view options for any Messages that are added to the diagram there after.
If you opened the View Options by right-clicking one or more selected Messages, the check boxes you select change the view options of those Messages.