Patent numbers: What you should know.

Patent numbers may seem straightforward, but they hold far more complexity than many people realize. Each number is like a fingerprint, with layers of information encoded in a unique combination of codes and identifiers. From country codes that change over time to kind codes hinting at a document’s status, patent numbers reveal a lot about a patent’s origin, purpose, and journey. But did you know that a single identifier can sometimes refer to multiple documents? Or that a patent number’s format can vary widely depending on the country? Dive into the details to discover what makes patent numbers both fascinating and challenging to decode.

• Most documents related to a patent are assigned a patent number as an identifier.
• The general structure of patent numbers is a combination of:
  • Country Code (per WIPO Recommendation St. 3)
    • Indicates the country or region of origin.
  • Identifier (per WIPO Recommendation ST.6)
    • Corresponds to a specific patent or application.
  • Kind Code (per WIPO Recommendation ST.16)
    • Specifies the type of document (application, grant, translation, etc.).
• Example: US 7592529 B2
• Not every country adheres to WIPO recommendations, so formats vary by country.
• Databases may introduce their own formats for patent numbers.
• Country Codes:
  • Change over time as countries do.
  • May be omitted in national patent office systems, as the country code is implied.
• Some represent broader procedures, like EP for European patents and WO for international patents filed under the PCT (Patent Cooperation Treaty).
• Identifiers:
  • Are not always unique and may be reused within a country.
  • Often contain both numbers and letters.
  • May include metadata such as the year, but these systems are generally inconsistent across all patents within a country.
• Kind Codes:
  • Are introduced over time and may change meaning.
  • Can indicate the legal status (e.g., whether a patent has been granted).
  • May be reused for the same identifier (e.g., a correction document might have a “B8” Kind Code, so multiple “B8” documents could share the same Country Code and Identifier).
• This means that patent numbers alone are not unique! The publication date is also needed to uniquely identify a document. However, even this approach can fail, for example, if an incorrect publication date is updated, leading to issues. To address this, organizations like the EPO have introduced unique document IDs in their DOCDB database.
• Patent numbers are not assigned by a global authority.
• Documents with patent numbers do not necessarily contain patent content; they may represent other documents, such as Supplementary Protection Certificates, etc.
  

Despite the complexities, patent numbers remain invaluable tools for identifying and tracking innovations worldwide. With a basic understanding of their structure and quirks, you can navigate the world of patents with greater confidence and appreciation for the system that helps protect ideas globally.