If you need to create your own SNOMED CT content or create a new SNOMED CT extension, you will need a unique Namespace Identifier allocated by SNOMED International. A SNOMED International Namespace identifier allows you to create globally unique SNOMED CT identifiers.
To learn more about our namespace allocation policy, please visit Namespace Allocation Policy. To browse the list of namespaces previously allocated by SNOMED International, please visit the Namespace identifier registry. And for more information, please visit http://www.snomed.org/snomed-ct/change-or-add-snomed-ct.