Section 306 - Use of trade publications(a) General rule.--Any government unit which is required by law to advertise for bids for public works, contracts, supplies or equipment, may, in its discretion, authorize the publication of such advertising, in addition to the newspapers authorized by the other provisions of this chapter, also in any publication or journal devoted to the dissemination of information about construction work published in this Commonwealth at least once a week and circulating among contractors, manufacturers and dealers doing business in the community in which such public works are to be constructed or supplies or equipment purchased.(b) Exception.--Except with respect to publication by any city of third class or borough, no advertisement for bids for public works, contracts, supplies or equipment shall be inserted in any publication or journal devoted to the dissemination of information about construction work, unless such publication meets the following requirements: (1) It has been established and regularly issued from a printing office and publication house in this Commonwealth for a period of at least 18 months.(2) It has been entered, or entitled to be entered, for admission to the United States mails as second class matter.(3) It has had a bona fide income from subscribers within this Commonwealth of not less than $15,000 per annum, duly certified by a public accountant.(4) The rates and charges for such advertising shall not be in excess of those of newspapers of general circulation of a like circulation published in the community in which the public works are to be constructed or the supplies or equipment purchased.1976, July 9, P.L. 877, No. 160, § 1, effective in 60 days.