Q) Retroactivity of Legislation

  1. Is retroactive tax legislation permitted?

  2. Is retroactive legislation commonly used?

  3. If retroactive legislation is not commonly used, is it used to curtail tax avoidance?

  4. Are there examples of legislation that are pending for long periods of time? (e.g. several years)

  5. Is there a requirement to provide transitional rules when legislation taxes something that was not previously taxed?