The syntax was specifically chosen to avoid confusion with other tag formats. XML could show up in any user- or LLM-generated text and would mess up the message format. Some variations even used unicode symbols like "｜" or "〈" to decrease the chance of confusion.
Also, back then, some people believed that it could prevent prompt injection, but history has shown that it was a futile attempt.
Also, back then, some people believed that it could prevent prompt injection, but history has shown that it was a futile attempt.