What are the requirements for openable windows in second storey construction?

To summarise (for full description you must read the entire requirement as stated in the BCA- the below is a summary only) the building code of Australia 3.9.2.5 Protection of openable windows states:

• In all second storey residential construction the openable part of a bedroom window must be restricted from opening greater than 125mm or alternatively a screen placed over the window and fixed to it which can withstand the force of a child (but not, obviously a normal insect screen).
• Other alternative methods include installing a child resistant device or ensuring that the window has a complicated, two hand opening system and is unable to be opened easily. (it is important to note that a lockable window does not comply becase the chance that the window may be forgotten to be locked, or that the key is simply left in the lock is too high)

​The full requirements are as follows:

3.9.2.5 Protection of openable windows

(a) A window opening must be provided with protection, if the floor below the window in a bedroom is 2
m or more above the surface beneath.

(b) Where the lowest level of the window opening is less than 1.7 m above the floor, a window opening covered
by (a) must comply with the following:

(i) The openable portion of the window must be protected with
a device capable of restricting the window opening; or
a screen with secure fittings.

(ii) A device or screen required by (i) must

(A) not permit a 125 mm sphere to pass through the window opening or screen; and
(B) resist an outward horizontal action of 250 N against the
(aa) window restrained by a device; or
(bb) screen protecting the opening; and

(C) have a child resistant release mechanism if the screen or device is able to be removed, unlocked or
overridden.

(c) A barrier with a height not less than 865 mm above the floor is required to an openable window

(i) in addition to window protection, when a child resistant release mechanism is required by (b)(ii)(C); and
(ii) where the floor below the window is 4 m or more above the surface beneath if the window is not covered by
(a).
(d) A barrier covered by (c) must not
(i) permit a 125 mm sphere to pass through it; and
(ii) have any horizontal or near horizontal elements between 150 mm and 760 mm above the floor that facilitate
climbing.
(ii) have any horizontal or near horizontal elements between 150 mm and 760 mm above the floor that facilitate
climbing.