The Brooklyn Museum has the following on its opening search page:
The material presented here represents only a fraction of that rich collection. The Museum is committed to making its collections accessible to the widest possible audience, and this site is an important part of that process. It is, however, a work in progress. We intend to continue to expand the number of works of art included on the site and to update information currently posted. We are making every effort to ensure that the information provided about our collection is accurate and up-to-date, but the nature of scholarship is that there are sometimes changes in information and new discoveries. If you believe you have information we should have about any of the works you find here, we would be happy to hear from you.
The Museum of Fine Arts, Boston shows this to start:
Note that some of the electronic records indicate that they have not been reviewed recently by curatorial staff and might need revision; also, please note that a small percentage of the MFA’s collection is not presently searchable online.The indicated MFA records have this:
This electronic record was created from historic documentation that does not necessarily reflect the MFA's complete or current knowledge about the object. Review and updating of such records is ongoing.That text is essentially identical to what appears on the Yale Art Gallery site
Note: This electronic record was created from historic documentation that does not necessarily reflect the Yale University Art Gallery's complete or current knowledge about the object. Review and updating of such records is ongoing.In turn, that's not so far off from the Harvard Art Museum text:
This record was created from historic documentation and may not have been reviewed by a curator; it may be inaccurate or incomplete. Our records are frequently revised and enhanced. Please contact the curatorial department listed above for more information.[[Note that I don't give a link into the Harvard website. The (almost unbelievable) explanation is that if you click on http://www.artmuseums.harvard.edu/collection/detail.dot?objectid=289448 you get a blank page. I clicked on the link from a search results page and saw information about a sherd of Roman pottery. Is it really possible that Harvard is checking a session id or the referrer and only displaying the info as part of an existing visit to the site? If so, that's highly (highly!) lame.]]
The Metropolitan Museum in New York has the following:
Due to the extremely large number of objects in the Museum's permanent collection, not all artworks are currently available in the Collection Database. Furthermore, information contained in the database records is, in some cases, incomplete, and all information is subject to change according to ongoing research and new acquisitions.The British Museum just puts "Noticed a mistake? Have some extra information about this object? Please contact us." on its individual object pages. That's in the same spirit as the more extended explanations from other institutions.
Overall, these texts represent a mode of sharing data that is welcome. Better to make slightly incorrect or outdated data available than to hold on tight to it. That's especially the case when there are images of the objects as well.