Journals publish what is often called the 'version of record'. But what if that version included errors, errors of transcription, or errors of fact? How would you know?

Suppose an article was updated, added to, corrected, or even retracted altogether because the research had been falsified - how could you find out?

That is the problem the CrossRef service set out to fix with the launch of its new project - still in pilot mode - CrossMark.

CrossMark will provide a system for readers to check the status of a document - whether it is maintained by the publisher in a consistent, standard way across different sites.

In addition, publishers will be able to use CrossMark to provide updates about corrections, retractions and withdrawals. Other useful data, such as whether the content was peer reviewed, what licensing terms apply, or information about funding, could also be provided by the same means.

Some publishers are already testing the service. The CrossMark pilot is now live at Proceedings B from the Royal Society, and several titles from the International Union of Crystallography. See an example of CrossMark in action.

More details can be found in this issue of CrossRef's quarterly report.