In any action relating to the use tax brought under the Relief Tax Ordinance, process may be served according to the Nevada Rules of Civil Procedure or may be served upon any agent or clerk in this State employed by any retailer in a place of business maintained by the retailer in this State. In the latter case, a copy of the process shall forthwith be sent by registered or certified mail to the retailer at his principal or home office. (Ord. 106 §11(E), 1989)