Does Twitter allow arabic usernames?

This is a non-standard, non-alpha-numeric, Arabic Twitter handle! This is the handle and not the username. Usernames concern themselves with the bio. A handle is the URL suffix for twitter.com used to identify an account, like the following:
twitter․com/‏ميمي العنزي
After Mikko's tweet, several people, including myself, tried to reproduce this anomaly. It turns out, there is little if any documentation on how, or even why this happened. I think in some rare cases, Twitter shows accounts in arabic that start with 0x. Like
twitter․com/0x0000
I've yet to reproduce this behaviour on Twitter though. One of my favourite replies to Mikko's tweet was by Mathias Bynens

@mikko Technically every Twitter handle has Unicode in it.

— Mathias Bynens (@mathias) May 12, 2013