Each UID used in DICOM shall be defined and registered in one of the following two ways:
⎯ DICOM defined and registered UID's
⎯ Privately defined and registered UID's
Both UIDs use the same encoding rules as defined in Section 9.1. See Annex C for a more detailed description of the UID registration process.
A limited number of registered DICOM Defined UIDs are used within the DICOM Standard. The organization responsible for the definition and registration of such DICOM UIDs is NEMA.
The registration process will rely on the publication of the DICOM Registered UIDs in PS 3.6.
Privately Defined UIDs are commonly used within DICOM. However, such UIDs will not be registered by NEMA. Organizations that define private UIDs are responsible for properly registering their UIDs (at least obtain a registered <Org Root>) as defined for OSI Object Identifiers (ISO 9834-1). The private organization defining the UID shall accept the responsibility of ensuring its uniqueness.