In the absence of a real agreement between the parties, custom can not impose contractual liability;1 although if there is a real agreement, many terms for which the parties have made no specific provision may be supplied by custom.2 In jurisdictions in which a contract between an abstracter and his employer is not intended for the benefit of subsequent purchasers of such realty,3 a general custom of subsequent purchasers to rely upon abstracts made for former owners can not impose a contractual obligation upon such abstracter in favor of a subsequent purchaser.4