Improper substitution of the term depth of focus in place of the term depth of field; the two are not even REMOTELY close in meaning!!!!
Another pet peeve I have is the newbie-speak of referring to "a high aperture", meaning something like f/11 or f/16. The term is a SMALL aperture.
With the flood of newbies into the photo game over the last decade, dozens of photographic terms are now routinely misused, all over the world, and all over the world wide web. "Don't get me started!"
"Focal point" for autofocus bracket location is another peeve.