[This is preliminary documentation and subject to change.]
No key property is defined for a scalar collection that maps to a class definition. In this case, there will be only one instance of the class definition. A class generated from a scalar collection will contain a class qualifier named Singleton that is of type Bool.
Each SNMPv1 and SNMPv2C table collection that maps to a class definition must contain at least one property that defines the object key; that is, a property that uniquely identifies an instance of a class. The INDEX clause of an SNMP table collection specifies the set of properties that define the keys of the class. The ordering of the INDEX information within the table collection defines the ordering of the keys within the class definition.
The CIM qualifier of a property that defines itself as a key is key, which is of type Bool. The CIM property qualifier that defines the ordering of the keys is key_order. The key_order qualifier is defined as an unsigned 32-bit integer value which, for the purposes of the MOF qualifier syntax, must be converted to a signed 32-bit integer value using the twos-complement operation.
Because of the flexibility of the INDEX clause within the OBJECT-TYPE macro, the specification of keyed properties is not straightforward. There are a number of possibilities to consider when mapping the INDEX clause to the set of keyed properties. The current mapping of the SNMPv2C INDEX clause does not handle the use of the IMPLIED qualifier. A class definition will not be generated in this case.