The "fake news" moniker may be a relatively recent one, but the phenomenon is not exactly new. Search engines and social media sites have long fought a battle against rogue news sources, and Microsoft's latest attack sees the company adding fact-checking to Bing.

The addition of Fact Check labels means that anyone looking at search results should be able to tell at a glance if a particular news story has been debunked. The label can be applied to sites as a whole as well as individual articles, making it easier for Microsoft to alert people about poor news sources -- although the company does not do any actual fact-checking itself.

Bing looks for schema.org ClaimReview markup when it scans pages and stories, and Microsoft has a number of recommendations for people before they use the tag on their site. Transparency of analysis is important, as are citation and references to primary sources. On top of this, stories must be written in such a way that readers are able to determine how conclusions were reached, and "the page hosting the ClaimReview markup must have at least a brief summary of the fact check and the evaluation if not the full text."

In a blog post announcing the feature, Microsoft says:

Bing is adding a new UX element to the search results, called the "Fact Check" label, to help users find fact checking information on news, and with major stories and webpages within the Bing search results. The label may be used on both news articles and web pages that Bing has determined contain fact check information to allow users to have additional information to judge for themselves what information on the internet is trustworthy. The label may be used on a broad category of queries including news, health, science and politics. Bing may apply this label to any page that has schema.org ClaimReview markup included on the page.

The presence of ClaimReview markup is not enough to pass the fake news test, however. Microsoft says that Bing will look out for sites that make use of third-party fact-checking organizations and widely accepted fact-checking methods. Sites that do not come up to scratch may find that their markup is ignored. There is also the threat of penalties for abuse of the ClaimReview tag.