Documents mentioned in recorded documents. Mortgage is not recorded. You better find out what happened to it. Reference to covenants in old deed. Restriction not in chain of title to WhiteAcre.
Buyer is subject to all recorded interests.
So, recorded history must be checked. All transactions for a piece of property are recorded in one place. Two sets of books. A list of transactions by grantees, by year. A list of transactions by grantors.