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18.3.13 EI - entity identifier (2A.3.25)

HL7 Component Table - EI - Entity Identifier

Core Framework Base Standard Profile
Seq# Description Interpretation Flags Cardinality Length C.LEN Vocabulary Data Type Implement Cardinality Vocabulary
EI
1 Entity Identifier [0..1]     ST      
2 Namespace ID [0..1]   noObject (CD VS) IS     (CS)
3
Universal ID
C

Condition defined for this element


[1..1]
[0..0]
    ST MAY    
4 Universal ID Type
C

Condition defined for this element


[1..1]
[0..0]
  universalIdType (CD VS) ID MAY   (CS)

Definition: The entity identifier defines a given entity within a specified series of identifiers.

The EI is appropriate for, but not limited to, machine or software generated identifiers. The generated identifier goes in the first component. The remaining components, 2 through 4, are known as the assigning authority; they identify the machine/system responsible for generating the identifier in component 1.

The specified series, the assigning authority, is defined by components 2 through 4. The assigning authority is of the hierarchic designator (HD) data type, but it is defined as three separate components in the EI data type, rather than as a single component as would normally be the case. This is in order to maintain backward compatibility with the EI’s use as a component in several existing data fields. Otherwise, the components 2 through 4 are as defined in Section 2.A.33, "HD - hierarchic designator". Hierarchic designators (HD) are unique across a given HL7 implementation.

18.3.13.1 Entity Identifier (ST) (2A.3.25.0)

Definition: The first component, , is usually defined to be unique within the series of identifiers created by the , defined by a hierarchic designator, represented by components 2 through 4. See Section 2.A.33, "HD - hierarchic designator".

18.3.13.2 Namespace ID (IS) (2A.3.25.1)

Definition: See Section 2.A.33.1, "Namespace ID (IS)" for definition. The component intentionally remains associated with the IS data type in v 2.7.

The assigning authority is a unique identifier of the system (or organization or agency or department) that creates the data. Refer to User-defined Table 0363 - Assigning Authority for suggested values.

Note: When the HD is used as a part of another data type, in this case as part of the EI data type, this table may be re-defined (given a different user-defined table number and name) by the technical committee responsible for that segment.
By site agreement, implementers may continue to use User-defined Table 0300 - Namespace ID for the first component

18.3.13.3 Universal ID (ST) (2A.3.25.2)

Definition: See Section 2.A.33.2, "Universal ID (ST)" for definition.

18.3.13.4 Universal ID Type (ID) (2A.3.25.3)

Definition: Refer to HL7 Table 0301 - Universal ID Type for valid values. See Section 2.A.33.3, "Universal ID Type (ID)," for definition.