UD Update Code

(a limit field)

200201 in ud

ud=200101-200112

The UD field contains a unique six-digit number, which is used to identify database updates. The first four digits represent the year the records were added to the database; the last two digits indicate the update number. Prior to 1999 (Volume 135), updates are added as whole years and carry "00" as an update number. From 1999 to 2000, there are four updates per year (numbered 01 through 04). From 2001 forward, there are 12 monthly updates per year numbered

01 through 12.

Browsing Update Codes

As an alternative to searching with the field label, you can browse update codes and search for them directly from the Update Code Field-Specific Index. This field-specific index contains only values drawn from the UD field, therefore, your search will always yield results. Search results display in the UD field.