René Scharfe [off-list ref] writes:
The lack of warnings about the use of that extension in po/ means
translated formats are not checked by the compiler at all, right?
According to the gettext documentation [2] msgfmt takes care of that
when building the translation files, though.
It is not even seen by the compiler at compilation time, right? _()
at runtime is merely a function call to map its parameter string to
another string using what is in .mo (compiled from po/).