As AppleInsider notes, the Review Guidelines were previously less concerned with cryptocurrencies, allowing an app to facilitate crypto and ICO transactions if it complied with the laws in the app's distributed territories.
Two sections have been updated in the new App Store Review Guidelines -section 2.4.2 (Hardware Compatibility) and 3.1.5 (b) (ii) (Cryptocurrencies).
Apple has a clear message for cryptocurrency enthusiasts: Don't mine it on our devices.
Cryptocurrency miners utilize large networks of devices, including iPhones and iPads, to help them mine.
Apple Publishes Revised Cryptocurrency, ICO Guidelines for App Store
That's actually what happened in the case of an app called Calendar 2, according to Apple Insider.
The upshot of the new rules is that while Apple will permit cryptocurrencies to exist on its platforms, it's adding requirements to stop scammers and individuals from exploiting App Store customers, while making explicit that it's blocking developers from eating Apple device processing power for mining activities. Any apps that facilitate ICOs, futures trading or other securities must be provided by established banks, securities firms and futures commission merchants (FCMs).
"Apps, including any third-party advertisements displayed within them, may not run unrelated background processes, such as cryptocurrency mining", the updated policy reads.
In sticking with the original mandate, only mainstream banks and similar financial institutions will be allowed to develop and publish apps enabling crypto futures trading and initial coin offerings, Apple said.
Four years ago, Apple removed every single bitcoin wallet application on its App Store, including popular wallet app Blockchain. In a dedicated cryptocurrency section, the company goes on to break down in more detail what is - and, crucially, is not - permissible.
France, Germany slam Trump's G7 statement U-turn
At the G-7 summit, Trump's spokeswoman, Sarah Huckabee Sanders, said the US was "close to a deal" on NAFTA. She said: "We won't let ourselves be ripped off again and again".