On nlwiki we have a number of articles where the title is an emoji. When no category sort key is provided, then the category page sorts most emojis under their own heading. However at least a few emojis are sorted using a different emoji. Obviously we should use explicit sort keys, but this looks like a collation problem so I thought it worth mentioning.

I created a test category on TestWiki, I hope that is OK. See testwiki:Category:Emoji.

As emojis are not really text, maybe they should have special first-letter handling?