Originally Posted by Raphael
ftn is the said abbreviation for "fortnight" (If I believe the Wikipedia page about the FFF system)
For ftm it's for "fathoms" units !
If you can fathom it, remember to convert "fortnight" to "fartnight" for Fred's part of its journey!
I do use a digital device in my photographic pursuits when necessary.
When someone rags on me for using film, I use a middle digit, upraised.