Data imprinting on the F2
Nikon made a special F2 body (F2 DATA) and two special backs (MF-10 and MF-11) that allow the user to imprint data information on the film. The F2 DATA is rare and hence very expensive. However, there is a much cheaper way to imprint data and personal information on the film, by customising a standard F2 body.

Basically, a narrow slot is milled out on the film window, and the same on the mirror housing back cover plate. The extra slot allows light through to a personalised mask, which then imprints the data between frames. This method is actually better than the usual method of imprinting, as the data information is not imprinted inside the exposed frame.

The data mask is made using a laser printer and a transparency film. Up to 15 characters can be allocated on each mask. The data modification service includes up to 5 personalised masks.
The mask is stuck to the body using double sided sticky tape, so that it can be changed if required Both the F2 body and the mirror housing back cover plate were cut out, to allow light through to the mask
The masks can be changed and reused.
Here is another mask with black background
Here's the actual results of a modified F2 I did for a customer. Making the masks is part of the service