Did you know that you can put a custom message or system status on the xMatters sign-on page? There is a file called SystemMessages.xml that will give users a message when logging in. It is located on the web server via the following path:
<xMatters Install Dir>/webserver/webapps/cocoon/alarmpoint/jsp/login/xmatters
Simply open the file, follow the directions within the enclosed instructional comment and enter your text. Save the file, then open the xMatters login page. Your message will appear under system status on the left. Easy cheesy.