== Telegraph == Back in the old days, telegraphs did not contain punctuation marks (okay, technically this isn't true: you could specifically request punctuation be sent, but this cost extra, was difficult to proofread on the operator's part and thus wasn't common.) To specify the end of a sentence, you'd write the word STOP. TO BE OR NOT TO BE STOP THAT IS THE QUESTION STOP (also, technically speaking, you'd write QUESTION to signify a question mark, but disregard that as well). This works handily well clearing up ambiguity in punctuation location, but introduces another possible ambiguity: what if the sentence has the word "stop" in it? I WANT A REBIRTH OF GLORY A RENAISSANCE OF POWER STOP I WANT TO (pause) STOP RUNNING THROUGH MY LIFE LIKE A MAN LATE FOR AN APPOINTMENT AFRAID TO LOOK BACK OR TO LOOK FORWARD STOP I WANT US TO BE WHAT WE USED TO BE STOP See, not that bad? For computers, however, it's a different story. Many thanks: http://www.telegraph-office.com/pages/telegram.html for the info. Also, Shakespeare and Babylon 5 for our telegraph messages. == Explain the metaphor == The message, TO BE OR NOT TO BE and THAT IS THE QUESTION is the *content* of the message. The STOPs are what we would call, in web applications, *markup*. (this metaphor will be used to explain the anatomy of an XSS hack, and will be extended for the HTML case)