pvdz.ee - 15.3.5.4 [[Get]](P)

function Function.prototype.[[Get]](P:string)

This function is kind of a proxy that prohibits getting the caller property in strict mode.

Code: (Meta Ecma)

Function.prototype.[[Get]] = function(P){
	var v = this.[[Get]](P); // todo: original [[Get]] function, 8.12.3
	if (P == 'caller' && v.strict) throw TypeError;
	return v;
}

Note that functions returned from Function.prototype.bind use the default [[Get]] method (8.12.3).