As reported onhttp://www.shusterman.com
(a respected immigration attorney site):
"...NVC No Longer Collecting Original Civil Documents – As of November 12, the National Visa Center (NVC) stopped collecting original civil documents (birth certificates, marriage certificates, police clearances, etc…) as part of the immigrant visa (IV) application process. Rather, IV applicants will now be instructed to bring their original documents with them to their interview. The NVC hopes that this will make the application process more efficient and reduce waiting times.
--Ray Bacon, 55/56