\include\staff\header.inc.php
line: 6
? $title : ('osTicket :: '.__('Staff Control Panel'));

line:96
<title><?php echo ($ost && ($title=$ost->getPageTitle()))?$title:'osTicket :: '.__('Staff Control Panel'); ?></title><?php

\scp\staff.inc.php
line:137
$ost->setPageTitle(__('osTicket :: Staff Control Panel'));

Client side:
\include\client\header.inc.php
line: 3
? $cfg->getTitle() : 'osTicket :: '.__('Support Ticket System');