5.01.07. An engineer who, in his advertising, mentions fees or prices shall do so in a manner that can be understood by the public, which has no particular knowledge of the practice of engineering or the professional services covered by the advertising, and shall:
(1) keep them in effect for the period mentioned in the advertising or, if no period is specified, for a period of 90 days following the last publication or broadcast;
(2) specify the nature and extent of the services included in such fees or prices;
(3) indicate whether or not certain fees are included in such fees or prices;
(4) indicate what additional services may be required which are not included in such fees or prices.