WoW:API GetGuildRosterShowOffline
Usage: showoffline = GetGuildRosterShowOffline();
showoffline = NIL if 'Show only online' check is marked on guild roster screen or if SetGuildRosterShowOffline() is set to disabled. Calls to GetGuildRosterInfo() will only return info for currently online members.
showoffline = 1 if 'Show only online' check is NOT marked on guild roster screen or if SetGuildRosterShowOffline() is set to enabled. Calls to GetGuildRosterInfo() will return info for all guild members.