http://blogs.msdn.com/b/officedevdocs/archive/2011/08/26/outlook-2010-mapi-reference-has-been-updated.aspxThe Outlook 2010 MAPI Reference has recently been updated on MSDN. The Nickname Cache topic is now in sync with my earlier blog post Programmatically Accessing the Nickname Cache in Outlook 2010 . What's New in This Edition lists the following updatesen-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)