Do I *need* `exit 0` at the end of `rc.local`?

What is the purpose of the exit code in rc.local? I seem to execute just fine without it. The header shows:

#!/bin/sh -e
#
# rc.local - executed at the end of each multiuser runlevel
#
# Make sure that the script will "exit 0" on success or any other
# value on error.

Who checks the return code? Does it default to 0 anyways?