Hi,
For Readability, I would put the extended use case in a separate diagram and refer to the other diagram with a note. In
Rose you can link the other diagram through the note. Communication is the key. If the sequence diagram gets too complex to communicate well than find a better way to communicate your ideas.
Also, avoid repeating the same sequence in every diagram.... for example the logon sequence which can be accomplished at different places in systems.
Noel
SCJP, SCWCD,
SCEA(PART1)