If you take a URL and paste it into your Facebook feed, Facebook pops up a little description of the site, and a "preview" icon for the site. Facebook can scrape this info from your page, but you can also give it specific info by using "OpenGraph" meta tags in the head of your page. Theoretically OpenGraph is an open standard, but in practice I think only Facebook's using it. :) The format is pretty simple, it looks like this (taken from the Mahara page templates): <meta property="og:title" content="{$PAGETITLE}" /> <meta property="og:description" content="{$sitedescription4facebook}" /> <meta property="og:image" content="{$sitelogourl4facebook}" />
See also: The Facebook documentation for OpenGraph: https://developers.facebook.com/docs/opengraphprotocol/ The Facebook debugger, which lets you test what Facebook would display as the "preview" for any given URL: https://developers.facebook.com/tools/debug The actual site for the OpenGraph standard: http://ogp.me/
This would actually be pretty handy for public libraries I think.
*** Bug 23935 has been marked as a duplicate of this bug. ***
It would be pretty darn nice if we could make our linked pages look nicer. There has been some improvement (I think), but it would be great to have a little more control.