The book contains a numbered list of signals used by East India Company ships, with separate signals for use at night or in fog. An index of imperative signals is at the back of the book. The book starts with an order of sailing with coloured flags, and general sailing orders and a list of ‘rendezvous’ locations for the convoy on route to Penang. This suggests the book was used by Pocock on the ST ALBANS when accompanying an East India Company convoy to China.