Assume that you sign in to Microsoft Lync for Mac 2011. In this situation, your display name might be displayed as the Session Initiation Protocol (SIP) address.
This issue occurs because Lync for Mac 2011 cannot parse a SIP to a display name.
Article ID: 2913470 - Last Review: Dec 12, 2013 - Revision: 1
Microsoft Lync for Mac 2011