The 1IM punt HTML tag that overloaded AOL’s own buffer <font size="199999999999…"> and fill the 9's to the end of the IM window.
I believe there was even a more effective one that was something like <font size="¿¿¿¿¿¿¿¿¿¿¿¿...">.
I believe there was even a more effective one that was something like <font size="¿¿¿¿¿¿¿¿¿¿¿¿...">.