Needs native check (English)

Sounds okay. However, it's a bit weird due to the combination of plural "ASCII quotes" and singular "a substitute". I'm not really sure how to resolve that though.

Certainly, native speakers (including myself) do say things like this very often, so you can remove the NNC.

It should be "real quotes" instead of "real" quotes.

Thank you for checking. ^^

@Archibald, what is your reasoning for that? It's fine either way. It just has a slight difference in meaning:

'"Real" quotes' would be quotes that are quasi-real.
'"Real quotes"' would be quasi-{real quotes}.
'Real "quotes"' would be real quasi-quotes.

In general, the position of the quotes matches the pauses in speech that a native speaker makes while saying the sentence to emphasize the separation of the quoted words.

I can imagine native speakers saying '"real" quotes' much more that '"real quotes"'. So I would have left it the way it was.

Well, I'm not a native English speaker. I thought "ASCII quotes" and "real quotes" should be treated the same way.

What I meant:
“ASCII quotes” is not really their name, as they can be found not only in ASCII (maybe they're from typewriters, I don't know, actually ^^), so that’s why I’ve put them in quotes.

“Real” is in quotes because ASCII quotes aren’t unreal either. :)

yep, you're right. I correct the French sentence too.