For what its worth, i believe the following to be true.

The issuers seem to know where the shares are held. For instance you dont get T-5 or T-3 slips for your dividends inside your RRSP. I believe the same information is available as when you trade there will be associated account numbers for where the shares are held, ie brokerage name and account type.

If there are any stock brokers out there maybe you guys and gals will know if this is infact the case.