Referenced on p.46 ELI - 58 The Janissaries by David Nicolle:
Janissaries and their officers approach the Sultan's tent while on campaign, from the Süleymanname (sic) of 1588. A row of triple-horsehair Tuğs stand inside a tented enclosure which is made to look like a fortress. (Ms. Haz. 1517, Topkapi Lib., Istanbul)