Not quite total reversal... the bankruptcy is recorded in TWO places: Your credit file, and the "National Personal Insolvency Index":
That's half right. I think you are right about the NPI, but I can tell you without a doubt that it disappears from your credit file very soon after you are issued with an annullment certificate. I even put this to the test by applying for a credit card without specifying what limit I wanted and was issued with a $20k card within days.
What you might be confused with is allowing the bankruptcy to come to it's natural end in min 3 years. I am referring to a Section 73 proposal that is accepted by the creditors.