Well, of course I'm in charge. Last time Steve did something he pushed the big red button that shut down the whole server room. If I weren't in charge, then it would just be "Steve"s everywhere. Anarchy. Who put the red button there? Who thought having the big red button there might be a stupid idea? That's not important. What's important is that Steve fucked up and I didn't. Remember: never trust Steve.
When people sit down to write open source, they write it the same way they would write code at work, because they've either never experienced anything better, or it was drowned out by the din. So their OSS is always almost as toxic as the situation I illustrated above.
If, for some reason, you want to leave dangerous things laying around, you need way more safety interlocks than an underscore. If you should never call a function, what's the harm in making it expensive to call? Use a function name where the only reasonable interpretation of calling it is that the developer consented, with full knowledge. Make the function name 60 characters long with some colorful adjectives. Name it after the OWASP recommendation that says what a bad fucking idea it is to call this method. Giant neon lights. Fireworks. And a marching band.
Do not look into laser with remaining eye.
https://hackage.haskell.org/package/bytestring-0.10.12.0/doc...
If the symbol is not exposed, then you can't get anywhere in the neighborhood of calling it accidentally. I think if you do enough object introspection you can still get the function handle, but you could never mistake the resulting code for being anything other than farm fresh, Grade-A Cheese.