»English - FAQ - Why do messages to and from some contacts are noted with '' and '', while for some others '<<<' and '>>>' are used?
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  http://www.micq.org/page.php?id=152

Author: , Posted: 19.02.2011 14:18.
The style of those indicates the transport mechanism used. '<<<' and '>>>' are non-acknowledged messages through the server, '<<' and '>>' are acknowledged messages through the server, '' and '' are acknowledged messages via a direct connection, and finally '%' and '%' acknowledged messages via an SSL-encrypted direct connection.