nested collaboration message numbers

[ncobbey]

On a collaboration diagram, is there a way to create messages with nested sequence numbers that have more than two levels?  (e.g., 1, 1.1, 1.1.1, 1.1.1.1, 1.1.1.2, ...)

"Topic: Version 3.60 - Build 635 Released  (Read 383 times)" (http://www.sparxsystems.com.au/cgi-bin/yabb/YaBB.cgi?board=Latest;action=display;num=1062401743;start=0#0) states "Added ability to number collaboration messages in indented groups (eg. 1.1.2.1, 1.1.2.2 ... etc)", but I haven't figured out how to get beyond two levels (e.g., 1, 1.1, 1.2, 2, 2.1, 2.2, ...).