This section applies—
to catering sales; and
to sales of milk to a person who carries on a business which consists of or comprises making catering sales (in this section called "a caterer").
Subject to this Part, a catering sale made in a specified area—
is lawful (unless it is for any reason unlawful apart from this subsection) if the caterer bought the milk under a sale for the purpose of which a special designation was used, or if he holds a licence authorising him to use a special designation in connection with the milk, whether the designation is used for the purpose of the catering sale or not, but
otherwise shall be unlawful.
Subject to this Part, on a sale of milk to a caterer, being a sale for the purpose of which the use of a special designation would be obligatory by section 40 if it were a sale by retail, the use of such a designation is obligatory, except where—
the caterer buys the milk with a view to subjecting it to a process to which milk is required to be subjected as a condition of the use of a special designation in connection with it, and he is the holder of a licence authorising him to use that designation; or
the caterer buys the milk for the purposes of a business of his as a milk dealer or a manufacturer of milk products other than his business as a caterer.
A person is guilty of an offence—
who makes a catering sale which is unlawful under subsection (2); or
who sells milk without the use of a special designation under a sale for the purpose of which the use of a special designation is obligatory under subsection (3).
A person is not guilty of an offence under subsection (3) if at the time of the sale in question he had reasonable cause to believe that the conditions specified in paragraph (a) or paragraph (b) of that subsection were satisfied as to that sale or that the buyer was not a caterer.
Section 47 applies for the interpretation of this section.