This is for files that do not specify a separate codeset at all, and for
interpreting a file that does specify one before it gets to the line with the
codeset directive, is my understanding, so needs to be there (for now, maybe
not in future). It maybe should be more explicit codeset changes
https://posix.rhansen.org/p/gettext_draft
Line 960
"Do we need to say this isn't used for message strings, only for parsing
the .po file?"
The .po file format has a mechanism for specifying the codeset of the
PO file. See line 1009. Therefore LC_CTYPE is *not used* for the
interpretation of the
