Unicode "no-op" Character?

[David Starner via Unicode]

On Sun, Jun 23, 2019 at 10:41 PM Shawn Steele via Unicode
<unicode at unicode.org> wrote:
> Which leads us to the key.  The desire is for a character that has no public meaning, but has some sort of private meaning.  In other words it has a private use.  Oddly enough, there is a group of characters intended for private use, in the PUA ;-)

Who's private use? If you have a stream of data that is being
packetted for transmission, using a Private Use character is likely to
mangle data that is being transmitted at some point. A NUL is likely
to be the best option, IMO, since it's unlikely that anyone expects
that they can transmit a NUL through an arbitrary channel, unlike a
random private use character.

-- 
Kie ekzistas vivo, ekzistas espero.