featured

 featured  is a proposed mf2 property (typically as ) for h-entry that indicates a representative image for a post.

Why
To indicate which image (among many potentially) should be used in summaries or other link-preview use-cases for a post.

How
Add the class name "u-featured" to the tag that you want used as the featured image for your post.

Ryan Barrett
uses u-featured occasionally on articles on https://snarfed.org/, since 2014-09-23:
 * https://snarfed.org/2014-09-23_brooke
 * uses  on an &lt;img&gt; tag inside the

Kartik Prabhu
on all articles on https://kartikprabhu.com/ uses "u-featured" on thumbnail images since sometime in 2015-??-??.
 * need permalink to first usage
 * retro-actively enabled on https://kartikprabhu.com/article/streets-india a post dated 2009-12-15 imported from old Blogger blog.

Michael Bishop
on all articles at https://miklb.com uses  for featured images inserted with the WordPress featured image feature. Since 2017. Wrote a little how-to accomplish with template tag or filter.
 * by its nature, retro-actively applied the class to all WP featured images.

Marty McGuire
on events on https://martymcgui.re/, since 2016-11-02:
 * https://martymcgui.re/2016/11/02/215844/
 * uses  on an &lt;img&gt; tag inside the

Chris Aldrich
on all articles at http://boffosocko.com with WordPress Post Thumbnails/Featured Images (retroactively since 4/25/17); also used selectively on posts since ~2/2017
 * Example:

Jacky Alcine
uses  on his representative h-card at https://jacky.wtf/about to show that the selected photo is the preferred one to be used.

IndieWeb wiki
The Template:featured can be used to put a class=u-featured image on a page, e.g.:
 * nostalgia
 * site-deaths

Bridgy
Bridgy Publish will detect a 'u-featured' photo in the absence of any 'u-photo' and use it, e.g. in a POSSE tweet since 2017-04-11.

More Use-cases
There has been thinking, starting in December 2018, that featured is an image that represents a post, regardless of the content of the post (beyond the banner image or first inset image in an article). Examples:
 * cover art for an audio podcast post
 * preferred photo to show-first (and in link-previews) for a multi-photo
 * thumbnail or album thumbnail / thumbnail grid for a multi-photo
 * video thumbnail for a video

Featured Images in Feeds
There’s at least one recommendation to use RSS’s element for feature images in RSS items. Example: 
 * 2012-08-30 Add Featured Images as Enclosures to Posts in WordPress RSS Feeds

And one to use Atom’s … element for featured images for Atom entries Example: https://example.com/featured.jpg
 * https://wordpress.stackexchange.com/questions/303704/adding-a-featured-image-to-atom-feed

It’s unknown if there are any consuming applications that parse these as expected and support displaying them as featured images. If folks can add specific examples (and perhaps screenshots) then we can move this to "How to"

Meta
On this wiki you can use the Template:featured to add a featured image to a page.