Paul
CAP393 is a collection of legislation. Section 1 is the Air Navigation Order. It consists of 134 numbered articles, and 15 Schedules, which are effectively appendices cited by the Articles. For convenience, the articles are divided up into parts, and Art 130 is in Part XI GENERAL, which is the part they put stuff in if they can't think of anywhere better.
Rather unhelpfully, they don't bother to number the articles in the bookmarks in the PDF version. The article is entitled
Public Transport and Aerial Work (which are the two other posibilities if a flight is not
Private). It does not win a plain English award, hence I was simplifying with my list.
130(8) is the paragraph that deals with the cost sharing exemption. That says:
no information concerning the flight shall have been published or advertised prior to the commencement of the flight other than, in the case of an aircraft operated by a flying club, advertising wholly within the premises of such a flying club in which case all the persons carried on such a flight who are aged 18 years or over shall be members of that flying club;
Flying club does not actually appear to be defined anywhere!