accessing the user interface to "supporting information"

I use BOTH TT Canada Standard (desktop)  and TurboTax US Deluxe (desktop)  for my filing requirements.  Since TT Canada uses the same interface as TT US why is there no "Add supporting information" option available in TT Canada.  will this feature be available in updated versions?  If there is now, how do I access it?.  this feature becomes important to  make notes as to what currency exch rate is used and its source when converting  dollars in either the Canadian or the US program.