If a browser loads a document containing an applet and discovers that it is unable to load the applet, this HTML will be displayed in the space where the applet was supposed to have been loaded.

However, this property cannot be set from an HTML tag attribute as the alt text can. It can only be set from a script.

Setting this property from a script is unlikely to be very useful, as the script is probably going to be called after the applet has failed to load.