You'll notice the example on the lower-right is "que".
The "q" words in Latin are very common (quibus, qui, quam, quo, etc.) and even a simple q-word can be abbreviated four different ways, with a line through the tail, with a squiggle above the q, with a straight line above the q, with an s-curve through the tail, and with the "z" shape as shown n Wladimir's example. If it's "quo" it can also be written as q with a subscripted "o". If it's quibus than there are two or three more options, with q'bz being one of them. The z is often substituted for "rem" and sometimes for "rum" rather than the more traditional "rum".
The top-page VMS marginalia that starts Allier uses the "z" shape at the end of a word which, in Latin, can mean lucrum or lucorum.
The "q" words in Latin are very common (quibus, qui, quam, quo, etc.) and even a simple q-word can be abbreviated four different ways, with a line through the tail, with a squiggle above the q, with a straight line above the q, with an s-curve through the tail, and with the "z" shape as shown n Wladimir's example. If it's "quo" it can also be written as q with a subscripted "o". If it's quibus than there are two or three more options, with q'bz being one of them. The z is often substituted for "rem" and sometimes for "rum" rather than the more traditional "rum".
The top-page VMS marginalia that starts Allier uses the "z" shape at the end of a word which, in Latin, can mean lucrum or lucorum.