This thread certainly had my curiosity piqued and I contacted a dear friend

from overseas to seek some clarifications. I think I now have a clearer understanding.
There appears to be an in-house lingo and customer terminology.
The reference to 'rack orders' is hinging on Hermes' in-house lingo. It's supposed to be RAC. Customers with FSH and can speak French, would be better able to understand / appreciate what RAC stands for. In our attempt to understand and apply this to our Hermes orders, it's best not to dream about RAC orders because these are really very, very few and far in between. It has very few rules, but not none at all because it has to pass H's design department. For example, if you want a customized size for your Birkin, or a bag design that Hermes gives you the honour to design. This is truly Hermes' Special Orders (Thank you,
TammyD for your explanation on this. It is what you said it is)
What we have been accustomed to ... what we commonly call "Special Orders" on tpf is what Hermes in-house terms as Personalisation Orders. For the past 2 years now, (I am getting a sense that FSH is in fact the last place to implement this) Hermes seem to have dictated to overseas H stores to conform these orders to the guidelines as shared by
KallieGirl. That is, the Version 1 to Version 4. And choosing colours allowed in the Personalisation Orders' list. Most SAs will refer to these as Special Orders anyway, because customers understand what it means! In order not to risk getting their quotas wasted and orders rejected, SMs have been following instructions to keep the combos according to what's stipulated.
In my honest and humble assessment of these terms, I am very sure VVVVIPs who have been offered RAC / Special Orders will know that their orders are truly RAC orders, because they pretty much have a free hand to decide what they want, subject to approval by H's design department. Imagine asking for a 32cm Birkin & it gets accepted. As posted before, these are so, so rare, we better not worry until we get our knickers twisted over them.