NL.16: Is initialization order a noteworthy exception to the rule?

NL.16 recommends that members be laid out in public, protected, private order.

Like many people, I do this as a matter of habit without giving it any second thought. Sometimes however the initialization order of members requires me to break this rule.

Something like:

class Foo {
private:
  int handle;
public:
  Foo () :
    handle(some_func()),
    width(handle_width(handle)),
    height(handle_height(handle))
  {}
  const int width, height;
};

... where width and height's initializers require handle to be set.

Is this worth stating as an exception?