Who broke the Beatles on iTunes story On Google News, it can be hard to tell.

Google wants to give news publishers a way to highlight their original work to better stand out in a content-repurposing world, but it relies on the honor system.

Two new metatags are available for news publishers to use on their Web pages when they want to highlight two specific types of content: stories that are shared with syndication partners and scoops or stories that are completely original works. Google announced the new tags in a blog post, and more specific details on how to implement the tags can be found here.

Publishers of scoops or detailed investigative reporting have long complained about the tendency for their links to get lost in Google News story clusters as thousands of other sites rush to cover the story. In addition, content syndication deals can lead to the story on the syndication partner's site ranking higher in Google News than the original story on the publisher's site.

The new tags are designed to solve those problems. The syndication tag isn't very complicated, as syndication partners can easily agree to use the tag on each of their pages to identify the true publisher.

But the original source tag creates new minefields for Google, already struggling to contain a mountain of spam inside Google News. Any news publication can claim to be the "original source" for a story on a given topic, and to be properly credited as that original source, other news organizations will have to agree to put the "original source" tag into their Web pages identifying that publisher, not just link to their content.

Google said that it might not be that hard to tell who is abusing the tag: If 20 publications credit CNET as the original source of a story, while one publication credits itself, Google should be able to tell that something is wrong with the one publication's tags.

But the notion of "original source" doesn't take into account incremental advances in news reporting, such as when one publication advances a story originally broken by another publication with new important details. In other words, if one publication broke the news of Prince William's engagement while another (hypothetically) later revealed exactly how he proposed, who is the "original source" for stories related to "Prince William engagement," a hot search term on Google today

Google doesn't really know. For that reason, it's rolling out these tags as an experiment: their use or non-use won't affect a story's ranking position within Google News.

"We think it is a promising method for detecting originality among a diverse set of news articles, but we won't know for sure until we've seen a lot of data. By releasing this tag, we're asking publishers to participate in an experiment that we hope will improve Google News and, ultimately, online journalism," Google said in a help page on the topic.

Google wouldn't comment on how long it would take for the company to feel comfortable it had enough data to start implementing ranking changes. It's working with "two big publishers" on the syndication tags, declining to identify the companies, but has done no testing on the original source tag as of yet.