I have a 16 2 (c) on my file as well, do you thinks we may get into deep secutiry cheking?
TL;DR version: this exemption is probably not related to the individual's file or some deep security check, or if so, only coincidentally - not worth worrying about. It's probably not about you.
S16(2)(c): exclusion from disclosure of information that could facilitate commission of an offence ... including (amongst other things) ... "(c) on the vulnerability of particular buildings or other structures or systems, including computer or communication systems,
or methods employed to protect such buildings or other structures or systems."
This is (c). I believe the
vast majority of stuff not disclosed under this section (c) is because sharing the info would also mean sharing technical information about the computer/communication systems and their protection (and why I bolded this).
In other words, it
probably is not about information in an individual's file but the system the information is from or is stored in.
Think about this from the govt perspective: they assume that
any and all information released under ATIP is "public." And that some nefarious party reading this stuff can use parts of that information to figure stuff out, even if the actual content of the information (your file) is of no interest.
For the analogy: think of signals intelligence in wartime. Collect enough signals traffic on boring stuff like how much cooking oil is delivered where and when, you might be able to figure out troop movements. It doesn't mean anyone cares whether Private Ryan individually likes fish and chips.