The following definitions apply to terms found in this subchapter:

(1) "Contact person" means the department representative designated to answer questions regarding the information contained in the administrative summons.

(2) "Interested person" means the taxpayer to whom the summons relates or any other person to whom the records or testimony pertains, including a third-party record keeper.

(3) "Records" means books, papers, and other data, whether in paper or electronic form.

(4) "Third-party record keeper" means, but is not limited to:

(a) an attorney;

(b) an accountant;

(c) a registered agent;

(d) a conservator;

(e) a bank or credit union;

(f) a broker-dealer or investment advisor; or

(g) any other person engaged in the making or keeping of records involving transactions of other individuals.