Richard Starkey is a headhunter with Taxman Company in Boca Raton, Florida. A key to Taxman's success is its accounting information system and, in particular, its list of employers and clients. The company prides itself on providing a good match between employers and clients, but does have repeats if a particular job placement does not work out. Each employer is identified by a tax identification number and each client by a social security number. These two tables should be related by:.