[Mailman-Users] English "translation"

[William Donnelly]

I'm using mailman version 2.1.13.

I've seen some web references to "English translation" files in

/messages/en/LC_MESSAGES/

But there is no such directory, or mailman.po and mailman.mo files.

Is this some option, or something some people have set up themselves, or
what is going on?

Why isn't that used so we can change text without having to
modify mailman python code and recompile, etc.?

I want to modify the page "code-generated" known as
"Confirm subscription request", among others.

Hints, help, support appreciated.

TIA