Sylloge Tacticorum is thought to have been written in the middle of the tenth century, and is a work on the making of order and organization of military forces (i.e. tactics), and ways to outwit and overcome opponents in the field of battle (i.e. through the use of stratagems).
It contained a description of tactics which would later serve as an influence on the tactical system described in Praecepta Militaria by Nikephoros II Phokas.
The word sylloge means, a gathering of information on something.
Sylloge Tacticorum Wikipedia
Heavy infantry men should have quadrilateral shields narrowing towards the bottom, prescribing the kataphraktoi shield.
Provides additionally instruction on religious rituals done prior to battle, and prayers to be recited upon victory.