The following directive was given by Napoleon to one of his officers prior to the 1806 Jena campaign. Note the clarity as well as the discretion granted to the officer.
Tomorrow at dawn you depart [from St. Cloud] and travel to Worms, cross the Rhine there, and make sure that all preparations for the crossing of the river by my guard are being made there. You will then proceed to Kasel and make sure that the place is being put in a state of defense and provisioned. Taking due security precautions, you will visit the fortress of Hanu. Can it be occupied by a coup de main? If necessary, you will visit the citadel of Marburg too. You will then travel on to Kassel and report to me by way of my charge' d'affaires at that place, making sure that he is in fact there. The voyage from Frankfurt to Kassel is not to take place by night, for you are to observe anything that might interest me. From Kassel you are to travel, also by day, by the shortest way to Koln. The land between Wesel, Mainz, Kassel, and Koln is to be reconnoitered. What roads and good communication exist there? Gather information about communications between Kassel and Paderborn. What is the significance of Kassel? Is the place armed and capable of resistance? Evaluate the forces of the Prince Elector in regard to their present state, their artillery, militia, strong places. From Koln you will travel to meet me at Mainz; you are to keep to the right bank on the Rhine and submit a short appreciation of the country around Dusseldorf, Wesel, and Kassel. I shall be at Mainz on the 29th in order to receive your report. You can see for yourself how important it is for the beginning of the campaign and its progress that you should have the country well imprinted on your memory.
[Source: Command in War by Martin van Creveld ]