Technology heavyweight Apple has clarified its App Store rules around nonfungible tokens (NFTs) and cryptocurrency exchanges, marking the first time its codified specific rules for NFTs.

The new rules confirm how NFT purchases will be taxed and what they can and can’t be used for while also clarifying rules around when a crypto exchange app can be listed. 

The Oct. 24 update to its App Store guidelines saw language added that allows for in-app purchases of NFTs, but bars any NFTs acquired elsewhere from being used for anything other than viewing. 

It also allows applications to use in-app purchases to “sell and sell services” related to NFTs such as “minting, listing, and transferring.”

However, the tech company is seemingly double-downing on its NFT “Apple tax” — which lumps in-app NFT purchases into its standard 30% commission rate on all purchases — by making sure all NFT purchases are conducted in-app. 

Apps won’t be allowed to include “buttons, external links, or other calls to action,” which could give users a way to circumvent app-store commissions when purchasing NFTs. It also prevents apps from using mechanisms “such as [...] QR codes, cryptocurrencies, and cryptocurrency wallets,” which could be used to unlock content or functionality within an app.

The rules come despite the company facing criticism for applying its 30% commission on NFT sales conducted through NFT marketplace apps such as  OpenSea or Magic Eden, a move that’s been marked as “grotesquely overpriced” when compared to the average 2.5% commissions on NFT purchases. 

Magic Eden said it removed its service from the App Store after learning of the policy and other NFT marketplaces have scaled back their application functionality with users only able to browse and view their owned NFTs.

Appl’s guidelines have also ruled out using crypto for in-app purchases, allowing only fiat currency purchases with a “valid payment method” such as debit or credit cards.

Related: Nodes are going to dethrone tech giants — from Apple to Google

The new guidelines make no changes to Apple’s existing policy on cryptocurrency trading apps put forward by exchanges such as Binance and Coinbase where trades are not subject to the 30% “Apple tax”.

However, new language was added to clarify that crypto exchange apps can only be offered in their app in “countries or regions where the app has appropriate licensing and permissions to provide a cryptocurrency exchange.”