SAP Note 10749 - Including customer tables for classification.

Symptom

Note: Including customer tables for classification

Solution
See 2.1 Release Information

Or

Customizing - Configuration menu - Central functions - Class system -
Assignment - Objects - Table - Help (Action bar). The documentation
is displayed with a reference to the release information. Double-
click to display.

Or

Written documentation:
MM Class System, Chapter 10

Key word: Class system