Mary, I got the birth register details from familyulster. His birth was registered at the workhouse under Annie Taggart, no father mentioned. Speaking to a member of the family again - even though he was obviously a young child when he heard this (from my grandmother's side), his exact words were "the mackays took him in and reared him". Could mean several things but how to link this Annie Taggart and Jackson Taggart to anyone else is not easy. I know PRONI will take a while to answer but I will write to them in Belfast and try to get access to the Minute books about his particular case even though those files will not be released for another couple of years. Either that, or I try another strand with the McKay side. It was only 1909 - there must still be a couple of eldsters alive who might remember him. So far I have stayed in the family circle or on-line - still got aunties.
Regards
Betty