Alerting images in dasboards

Dear all, do you have any idea about putting some images in dashboard?
I just want to put there some kind of notifiers.
For example, i have a dashboard on my RT-at-glance with a list of tickets.
Can i somehow put there small “graphic” notifier about, for example
ticket overdue?
I tried to put some html code in Edit Query -> Advanced -> Format
(text area by default contains something like :

QueueName’, etc

but RT seems to delete html tags like .

Can you please give me a hint?
Or maybe anybody knows a list of different tags like /TITLE, etc?

Thank you in advance.

Regards, Alex.