How to write currency codes for cryptocurrencies?

For "normal" currencies there is usually a sign (e.g. $, €) and a code (e.g. USD and EUR) to denote that a number is a monetary value. Depending on your locale setting the sign can be written before or after the amount (variously) and the code (correct me if I'm wrong) can be written strictly only on one side or the other. For example, in Sweden we write 10€ and 10 EUR but in the UK they write €10 and EUR 10.

My question is: how it should be treated in the world of cryptocurrencies? Those currencies don't have any symbols, only codes (depends on how you see it). Should they be treated as "real" currencies and have the code placed depending on localization? I'm confused because I've never encountered any situation where it's written ETH 10 instead of 10 ETH.