Comment 4 for bug 1808450

> No need to mansplain.

I was answering your previous "Not all languages use English quotation marks."

> Better explain to me something I don’t know: why is this the first time a new placeholder “%q” has been needed?

It's not the first time a language has a field specifier that's not part of C's printf. Python has %r for example, which means "pass the argument through repr()". Similarly, Go has %q which means "Treat as %s, but then pass it through strutil.Quote before actually printing".
It's a convenience.