Contractors - do you know where to find a copy of the Post Guide?Contractors will find that the Post Guide is extremely useful for resolving misunderstandings and disputes. It contains information on a wide variety of topics, including location of letter boxes, carriage of fluids in the mail, dangerous goods, and maximum size and weight for parcels.There should be a copy on display at your DC or originating office. If you don’t know where to find a copy, make it your business to find out!