[voraa]

в английской версии уже нет этого пункта.

Может в другом месте, но есть

Second, strict mode prohibits function statements that are not at the top level of a script or function. In normal mode in browsers, function statements are permitted "everywhere". This is not part of ES5 (or even ES3)! It's an extension with incompatible semantics in different browsers. Note that function statements outside top level are permitted in ES2015.

'use strict';
if (true) {
function f() { } // !!! syntax error
f();
}

for (var i = 0; i < 5; i++) {
function f2() { } // !!! syntax error
f2();
}

function baz() { // kosher
function eit() { } // also kosher
}

https://developer.mozilla.org/en-US/...ce/Strict_mode