Well, a ketch is a sailing vessel with two masts, the recognized description being that the mizen is stepped before the rudder-head, while in a yawl it is stepped abaft it. This, however, is not an exact definition, the true difference between the two rigs depending more on the size of the mizen-sail; if the difference depended on the position of the mizen-mast, most of the yawl-rigged beach boats would be ketches.
Actually, it is a so-called "Marine-Kutter", which is no cutter but a ketch with a cutter rigging.
Can be used both as rudder boat (had to do such in the first month of my Navy career
) or as a sailing boat (was sailing the Kiell-week twice [as reserve exercise]
You are correct about the sticker :wink: (Honestly, our boats had "real" Nato numbers during the Kiel week "Y-something")