Unicode "no-op" Character?

[Alex Plantema via Unicode]

Op zaterdag 22 juni 2019 02:14 schreef Sławomir Osipiuk via Unicode:

> Does Unicode include a character that does nothing at all? I'm
> talking about something that can be used for padding data without
> affecting interpretation of other characters, including combining
> chars and ligatures. I.e. a character that could hypothetically be
> inserted between a latin E and a combining acute and still produce É.
> The historical description of U+0016 SYNCHRONOUS IDLE seems like
> pretty much exactly what I want. It only has one slight disadvantage:
> it doesn't work. All software I've tried displays it as an unknown
> character and it definitely breaks up combinations. And U+0000 NULL
> seems even worse.

DEL was used as such on papertape to replace errors.

Alex.