'It was an incidental cause'
incidental means not a major part of something. His injuries were a result of incidental damage. That is an incidental fact, not related to the main argument.
Having the fastest time was incidental to winning the race.
I tripped, incidentally, my enemy's leg was out where I had tripped.
After discovering that his partner was embezzling from their firm, the man shot the culprit; the fact that his partner was also having sex with the man's wife was incidental.
The Incidental Economist was created in 2009.
A parenthesis is used in a sentence to indicate that you wish to interrupt your own sentence to include some comment or information that is incidental to the actual point of statement that your sentence is making. This is actually quite similar to the use of commas, which are used to separate different clauses of a sentence so that they don't all run together, but the parenthesis does so with greater emphasis, it sets something apart more forcefully than commas do.
Physical safeguards are
all the above
all the above
Established appropriate physical and technical safeguards
all the above
Established appropriate physical and technical safeguards