Possible Clues:

• Justification for silence
• It contains a due process clause
• Constitutional revision is fine, provided that includes darn guys
• Change Guy Fawkes night? Avoiding answers, I take it
• In US this gives the right to remain silent
• (e) - last word to many in depression - you don't have to incriminate yourself
• In US constitution it prohibits double jeopardy
• Change after interval often taken in American courts