Starting mid November 2007 UNSD publishes a Publication Note for every newly released dataset.

The Publication Note indicates whether the data for this country year is published for the first time, whether we are publishing newly received updated data or whether data has been re-processed (and is getting published again) for a particular reason. In addition, it is indicated when and from/ through whom we received the data.

There are three principal reasons for revising already published data:
(1) to bring existing data in full compliance with the standards and to generate the outputs of the new Comtrade processing system which has been established 1. January 2006,
(2) to make corrections to the data and
(3) take into account revisions in the conversion factors used to convert original data from national currency into US dollar.

The Publication Notes are available under "Metadata & Reference" or directly at the following webpage: