These should be listed as BOTH banknotes AND coins.

Look here;

https://www.youtube.com/watch?v=IIl6oTQxpl0 .

Aidan.

What makes them banknotes? They are just as “coin-ish” as any other coin.

Carol51

What makes them banknotes? They are just as “coin-ish” as any other coin.

They have banknote designs.

Goznak produced them 

Aidan.

They are hard plastic coins, very inflexible. Not banknotes whatsoever,

These arguments don't hold much water, it's plastic you can print anything you want on them unlike die cutting were you have quite few limitations. Also Goznak are responsible for some coin manufacture since 1941.

Unrelated to the transnitrian coins but i just bought a cardboard coin:

N#152486

Clearly coins, pure and simple. 

The fact it was printed makes no difference, otherwise any other coin with printing on it would be called banknotes such as cardboard coins, coins with printed designs on them, or coins that were made out of cardboard discs with stamps on them. 

Something similar was discussed a couple of years ago. I believe the consensus at the time was rigid → coin, flexible → banknote.

 Moving cardboard coins to banknote section or removing cardboard coins from banknote section. [solved] – Numista