A number used to identify the meaning (or status) of the data which immediately follows the GS1 Application Identifier (Internal).

Notes:

The explanation of the National Code descriptions are:

• Hospital Identifiers: identifies that the data immediately following the GS1 Application Identifier (Internal) relates to local hospital identifiers, typically ORGANISATION IDENTIFIER (CODE OF PROVIDER), LOCAL PATIENT IDENTIFIER (EXTENDED) and the ORGANISATION GS1 GLOBAL LOCATION NUMBER.
• Baby Details: identifies that the data immediately following the GS1 Application Identifier (Internal) relates to baby details, typically NUMBER OF BABIES IDENTIFICATION CODE (PATIENT IDENTIFICATION), PERSON FAMILY NAME (MOTHER OF BABY) and PERSON GIVEN NAME (MOTHER OF BABY). 
• PATIENT Descriptive Data: identifies that the data immediately following the GS1 Application Identifier (Internal) relates to PATIENT descriptive data, typically PERSON FAMILY NAME, PERSON GIVEN NAME, DATE OF BIRTH (PATIENT IDENTIFICATION) and TIME OF BIRTH (PATIENT IDENTIFICATION).
• General Data: identifies that the data immediately following the GS1 Application Identifier (Internal) is the 2 character code '00' followed by a PATIENT GS1 Global Service Relation Number. Note this Code is NOT valid for the AIDC for Patient Identification Data Set. All other uses of GS1 Application Identifier (Internal) '94' are reserved for future use.

National Codes:

Notes:
Codes 95-97 have been reserved for national use only, and are not to be allocated by the NHS locally. Codes 98 and 99 can be allocated by the NHS for local use.

Further guidance can be found on the NHS England website at: DCB1077: AIDC for Patient Identification.

This attribute is also known by these names:

Context	Alias
formerly	GS1 APPLICATION IDENTIFIER (INTERNAL)
plural	GS1 APPLICATION IDENTIFIERS FOR INTERNAL