The BASIC version is the simplified version of the more complex underlying ECLASS data model (ADVANCED). Certain structural elements are not displayed, e.g. the application class. The relation Classification Class - Application Class - Property - Value list - Value is simplified to Classification Class - Property - Value.
With release 7.0 the BASIC version was changed, e.g. the unit was introduced as a distinct structural element having a relation to a property. A lot of typing errors were corrected with this measure and a huge step taken towards standardization. Plus, a distintion was made between value lists and value templates. The following figure shows the BASIC version in 7.1, LanguageCode=en.
The versions before release 7.0 (i.e. 3.0 till 6.2) were kept more simple, e.g. the unit was only a free text attribute of the property, therefore resulting in a lot of typing errors.