Missing or wrong internal references. Especially for the case of potential and signal equivalences the error of wrong pin references occurs. Generally formulated: A correctly classified part in general represents a tree structure where the branches are described through references. If there the necessary internal consistence of the tree is broken, an error of this class occurs.

Following figure shows correctly classified potential equivalences referencing the existing connection identifiers (EB_... to EC_...).

The next figure shows an incorrect reference to the non-existent connection identifier EX_1111.

In this case, validate.dat contains an error message of the following type:

Invalid XML Verweis auf eine nicht deklarierte ID ist 'ID_PIN7'.

Note: The connection identifier and comparable internal tree references get numbered names differing from the CNS definition. This is a limitation of the XML format, which does not exist in the CNS classification in this form. However, they always start with "ID_".