Swarm has had a feature for a long time where you can allow your friends to check you in. It's more than just tagging a friend in a checkin, since it actually creates a full-fledged checkin on the other person's account. It's an interesting feature of Swarm, and not something I've seen elsewhere.
Today I shipped an update to OwnYourSwarm which will include that information in the Micropub request it sends to your site.
Here's a checkin from last night that was created when anomalily checked me in.
Here's what it looks like on my site now.
To accomplish this, I added a new property in the Micropub JSON that OwnYourSwarm sends. The property is checked-in-by and the value is an h-card of the person who checked you in. There was some discussion about whether this should be shown with the person who checked you in as the author, but I argued against that since on Swarm the checkin appears in your own checkin history and is otherwise identical to a checkin you created yourself.
"checked-in-by": [ { "type": [ "h-card" ], "properties": { "url": [ "http://anomalily.net/", "https://foursquare.com/user/894076" ], "name": [ "anomalily" ], "photo": [ "https://igx.4sqi.net/img/user/300x300/894076-UEP315CWOZJNKG2J.jpg" ] }, "value": "http://anomalily.net/" } ]
If you are using OwnYourSwarm's JSON format, you'll start receiving this additional property right away! If you've followed the Micropub spec and are already storing unrecognized properties in your storage, then you can later add support for rendering this property like I did!
Happy Swarming!