SAP Note 11189 - Including a field in the incompletion log .

Symptom

Not all SD document fields can be maintained in the incompletion log using Customizing.

Cause and prerequisites

As a standard, a catalog is delivered with the fields that can be
maintained.

Solution
Please inform SAP develpement if additional fields are required.
As of 3.0c Customizing is simplified so that the problem no longer exists.

Key word: Incompletion Log