I don't know if it's actually mentioned anywhere in the documentation. The actual specifics of the DX spec that the vendors conform to isn't publicly available, unfortunately. I'm pretty sure that the OpenGL spec explicitly mentions it somewhere, but it would take me a while to dig through that and find it.
Handling depth sorting key and hardware instancing
So in the end this means that I can't do instancing with transparent objects since I need to sort them ? :(
Hello
In my program, I use a deferred renderer for opaque geometry with hardware instancing, (even for single objects ...) (because I massively repeat lots of identical objects, just changing some parameters like scaling, texture index ...).
I never render transparent geometry using instancing, because, mainly, my techniques can need several passes (screen-space refraction, front culling rendering then back culling rendering ...), I use a lot of different vertex layouts and techniques, so I need several draw-calls anyway, at least to change them. And because I prefer change all these states rather than not respect this minimal (mesh subsets) depth order.
This is just what I do, not an advice, so feel free to correct me So, in my opinion, to answer to your question, yes.