The handling of accessory parts in eClass Advanced provides the basic concepts for the CNS classification system. Because of this we will have a detailed look on it.
Typical example of accessory parts in eClass Advanced: The first marked connection (black) has no potential accessory parts. This is in contrary to the second connection (red), whose accessory parts are specified in the subfolder "AAQ675"" [Part relation/Teilebeziehung].
Representation of above situation on the side of CNS classification: Data in the class "CNSELEK|5|4" both contain eClass data (see above) and the "bookkeeping", which links the eClass tree structure with the usual PSOL accessory logic (see below).

![Typical example of accessory parts in eClass Advanced: The first marked connection (black) has no potential accessory parts. This is in contrary to the second connection (red), whose accessory parts are specified in the subfolder "AAQ675"" [Part relation/Teilebeziehung].](https://webapi.partcommunity.com/service/help/latest/pages/cn/partwarehouse/doc/resources/img/id2022.png)

