These two digits further specify the geographical location of the winery by adding the State or Wine Region.
For example: for the United States and Italy, RR represents the different States. In Germany and France RR represents the official wine regions in the country. In France, 01 is Bordeaux, 02 is Burgundy, 13 is Champagne and so on.

When the RR digits are not a numerical code but alphanumerical characters such as "TT" or "TB", this means the data originates from an unofficial third party source which may include retailers and consumers. This data has not been validated by the wine producer or the ISWN organization, and may contain errors (see below).

Note that these two RR digits would theoretically not be required from an information management point of view, as an incremental number counter for the wine producer per country would suffice. However, the RR digits were designed into the ISWN code for the following reasons:

• user convenience requirement for the ISWN to be a transparent and readable code
  The RR digits make the ISWN code much more readable for consumers, as RR allows to further locate the winery or distinguish wines by interpreting RR on top of the ISO country code. This also makes it easy to sort and access data in electronic catalogs, or restrict choices in computer search engines.
  
  
• wines are considered by their originating 'wine country'
  The above soft argument becomes a hard requirement when taking into account that users think of wines by their origin, and these 'wine countries' do not correspond with the official ISO countries.
  To illustrate this consider wines from Bordeaux and Burgundy (two different 'wine countries' in France), or California and Washington (also two different 'wine countries' in the United States). The RR extension to the ISO country code is intended to denote exactly this world of difference for the consumer.
  
  
• implementation of the ISWN code
  The design of the ISWN code included the implementation requirement that internet technology would be used for establishing a complete global reference index of wine producers and wines in the most effective way possible.
  Multiple information suppliers and sources were consulted to populate the base ISWN database in 1999. However, all third-party data may contain errors which can only be corrected when a wine producer supplies the official and correct information directly to the system (see Registration info).
  Therefore, the RR digits are used to flag data input by other sources and distinguish data which has been validated by the ISWN organization. Whenever the RR digits are not a numerical code but alphanumerical characters such as "TT" or "TB", this means the data originates from an unofficial third party source which may include retailers and consumers.