Bush's campaign against Al Gore: At second 26 you can read the word “Rat"

What is subliminal advertising?
Subliminal advertising is one that uses words or images (that is, stimuli) that we do not consciously detect.

These stimuli may be imperceptible because they are hidden within another image, or because they are presented to us on the screen so briefly that we are not aware that we saw it.

What is the maximum time an image has to be exposed on a screen to be detectable? Often common practice is 0.003 seconds.

Most people will not be aware that their brain perceived a stimulus it was exposed to for 0.003 seconds.