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Component Definition

Although each component is of some type, the components themselves can only be defined within a type assignment that has a base type which is a constructed type, that is, one of SEQUENCE, SEQUENCE OF, SET, SET OF, or CHOICE. Hence to define any components within a map at least one type assignment referencing one of the constructed types is required.

For a data component to be usable, ASN.1 only requires it to have a type. The compiler requires that the component is named (except in some circumstances discussed later). The component name must be unique (in its uppercase form) within the construct in which it is defined, and is the name used by NCL to reference that particular data entity.