38. Keeping of documents: The operator shall keep the following documents:(a) his registers and landing bills, by order of date, for at least 2 years from the date of the last entry or the date they were filled in;
(b) his invoices, by numerical order for at least 2 years from the date on which they were made; and
(c) the weight cards, by numerical order for at least 1 year from the date of the weighing.