Mark I, Mark II, Mark III, Mark 567,900 and a half...

It has been a tradition for aircraft developed by the British that each successive  important development of a particular airframe has received a sequential Mark number. As the British are all classicists at heart, these numbers are written in Roman numerals. But eventually they ran out of paint, or space on the fuselage, or erks that could read Latin, and had to succumb to using regular numbers

Thus we had Supermarine Spitfires that went all the way up to Mk.47, but chickened out about the Mk. XXIV as far as the  numerical designations. Had the RAF employed curates, prelates, and bishops to maintain the aircraft they might have got up to Mk. XLVII and brought a bit of ton to the station...

Some camera makers have followed suit - we have Mk.II and Mk. III versions of a number of cameras, and even a Mk. IV from one proud oriental firm. Not a bad thing in itself, but combined with other designatories, the whole the starts to be an alphabet soup. A Flapoflex 1DXCS D3o,ooo Mk IVSP-K2 is a wonderful camera but the model plate hangs over the edge of the body and pokes in your eye...

There are times when I wish they would take a leaf from the modern Romans who label their excellent tripods with things like MK294A3-AORC2 or 755CX3-M8Q5.

It makes it so easy to find things on the storage shelves...