I would assume the 6.65oz mark refers to the weight of the tankard
That`s why I asked for the weight. Fluid ounces (6.65) are not matching three quarters of the pint (Imperial British measures).
It`s definitively not a measuring tankard (having in mind elaborate decoration). On the other hand, it can be used to measure the capacity and weight of any dry stuff put into it if the weight is known, being 6.65 oz.It`s not seen too often in nicely decorated tankards, so I am really interested if you could provide its weight. If it`s 6.65 ounces then we have the answer.