J_Darnley - haha, I had to think about that for a minute. And yes, they make things more complicated, especially when you invent new ones, but they do save on typing, too. For command lines arguments, I like it when both a long form and short form argument are defined. For general usage, though, a minimum of abbreviations is best, since communication is the objective.
I assume sample aspect ratio was named that because the concept of "sample" was somehow better or more forward-thinking than pixel, but pixel is the common person's term for the addressable picture elements (hey, how about APE
), and I would think I knew what "PAR" was in this context without prior experience or reading the manual.