The ASN.1 ABSTRACT-SYNTAX class is a useful class definition used to declare the top-level protocol data units (PDU’s) defined within a specification. The class is described using the following ASN.1 definition:

   ABSTRACT-SYNTAX ::= CLASS {
      &id OBJECT IDENTIFIER UNIQUE,
      &Type,
      &property BIT STRING { handles-invalid-encoding(0)} DEFAULT {}
   }
   WITH SYNTAX {
      &Type IDENTIFIED BY &id [HAS PROPERTY &property]
   }

ASN1C is used to create a meta-definition for this structure. The definition will be generated in the file Asn1AbstractSyntax.cs (or Asn1XerAbstractSyntax.cs for XER), if needed by compiling ASN.1 definitions. An object created from the resulting C# class is populated just like any other compiler-generated structure for working with ASN.1 data.