Question about deckchecks and cards not listed on rk9 decklists but are legal for play

[NotAMouse]

Someone asked on a Reddit thread what to do when a card they want to use (Flittle from 2023 McDonalds collection) isn't listed as an option on the Rk9 decklist and they need to submit a decklist for regionals. The original card that it's a reprint of in Scarlet and Violet base is listed on Rk9 so would it cause issues during a deckcheck if they use that SV card details on the decklist but included the McDonalds version in their deck?

Comments on the thread are saying explain the substitution if deckchecked but I was interested in what would actually happen. I'm also curious as when I looked on the legality lists here for both Standard and Expanded some of the more recent McDonalds sets aren't listed so does that mean that they aren't legal for either format or it's just an oversight?

Many thanks

 

[BJJ763]

The deck must match the deck list. If deck checked, you'd have to replace the McDonald's card with the one listed on your deck list.

The deck list has McDonald's cards having their own set symbols so sounds to me like an oversight.

 

[PokePop]

I'll also note that if a card is equivalent in game terms, a deck check team should give nothing higher than a warning. And if there is an error in RK9 that leaves that card out, not even that after an explanation.