As a curiosity...

When it comes to booleans, in YAML you can use y, YES, on, True and other variations for the true value.

As you probably guessed, for the false value, you can use n, NO, off, etc.

But NO is also Norway's ISO 3166-1 alpha-2 country code. Oops. Edge case.

Of course, you can just escape it, as this article rightfully suggests.