In this section the following words have the meanings indicated. “Directory information” has the meaning stated in 20 U.S.C. § 1232g. “Personal information” means: an address; a telephone number; an e–mail address; or directory information. A custodian of a record kept by a public institution of higher education that contains personal information relating to a student, a former student, or an applicant may: require that a request to inspect a record containing personal information be made in writing and sent by first–class mail; and deny inspection of the part of the record containing the personal information if the information is requested for commercial purposes.