>Okay, I understand this. Does it imply that 'retroactive' is not applied to the years since 2005? My understanding of the word in relation to taxes is that the adjustment of the law will be effective as of a date prior to enactment.

I think it is going back up until 1991. But, this can only apply to those having ongoing issues on appeal cases. Because, those who could have been in similar situations, where the CRA would have requested them to pay some uncollected taxes, if they would have accepted to pay it and not go on appeal, this would have meant they wouldn't have been eligible to request a reimbursment on those payments.