Do Split cards need to be the "right" way up?

[short plover]

I had a look through the game rules and I can't spot anything prescribing what way up cards need to be in your deck. (Did I just miss it?)

This leads into two questions:

• Can cards in general be placed upside down in opaque sleeves?
• If no, Can Split cards?

The reason I'm asking is because fanning split cards as a left handed player causes them to display no card names (and also just the "life" or "shock" art) making them very hard to identify. (This also potentially choreographs to an opponent what is in your hand because you have to rearrange the hand to see).

Fanned cards with ???//life card the correct way up.

Fanned cards with ???//life upside down.

[wooden helm]

I can't see any reason why you have to put the card in a specific orientation in the sleeve
The only rule it could run afoul of is marked cards where you can spot the card from a pile of other cards in your deck while they're all facedown.
So the card can be in any orientation in the sleeve as long as you always keep the sleeves in the same orientation

[vestal dome]

Yeah, it can easily fall into marked cards if the sleeves aren't all in the same orientation, besides that, unless there's something in the TRP, I don't see any issues with it