The Office of the National Coordinator for Health Information Technology is soliciting public comments on a set of "metadata" standards intended to facilitate exchange of health information. The move signifies the U.S. Department of Health and Human Services is getting ready to propose rules for metadata that could be incorporated in Stage 2 of the "Meaningful Use" incentive program for electronic health records. Building on the recommendations of the Health IT Standards Committee and Health IT Policy Committee--advisory panels to the HHS secretary--ONC is looking for answers on 20 specific questions about elements of metadata in electronic health information. ONC defines metadata as "data about data," or "data that provides more information or detail about a piece of data. We believe that the use of metadata holds great promise and the adoption of metadata standards can help rapidly advance electronic health information exchange across a variety of different exchange architectures," ONC said in its advanced notice of preliminary rulemaking, a prelude to a formal regulatory proposal.