If it were me, I’d drop the Notes and Warnings (never been a fan), and put Thing #2 first, and then Thing #1. Maybe something like

'''
sys.exit([arg])

Exit from Python. . . . and it is possible to intercept the exit attempt at an outer level. When called from a thread other than the main thread, this causes the thread to exit silently instead, and is equivalent to calling :func:`thread.exit`.

The optional argument *arg* can be an integer giving the exit status (defaulting to zero). Passing ``None`` is equivalent to passing zero. Any other object is printed to `stderr` and results in an exit status of 1. In
particular, ``sys.exit("some error message")`` is a quick way to exit a
program when an error occurs. When called from a thread other than the main thread, nothing is printed and the argument is ignored.

An exit status of zero is considered “successful termination” and any nonzero status is considered “abnormal termination” . . . Unix programs generally use 2 for command line syntax errors and 1 for all other kinds of errors.
'''