In November 1806 the king wrote down some "Instruktionen und Entwürfe":
https://books.google.de/books?id=kz0UGg1TJ4UC&pg=PA295&dq=1
which were, only slightly altered, issued in Osterode on 23 November 1806 as "Instruktion für die Generale bei der Armee in Ostpreußen.":
https://books.google.de/books?id=cWJDAAAAcAAJ&pg=PA717
Both in German only, sorry.