A simple way to limit the amount of classes of a model type in the modelling panel is to use the Mode option in the View menu.
In order to define a Mode option you have to use the keyword “MODE” in “Library attributes/Add-ons/Modi”.
For example we have the following:
modeltype: Sample
classes:A, B, C, D, E
relation classes: anyRany, aRb
You could e.g. show all classes in the Mode called “All classes” and only the modelling classes in a Mode called “Modelling classes”. The code for this would look like the following:
1MODELTYPE "Sample"
2INCL "A"
3INCL "B"
4INCL "C"
5INCL "D"
6INCL "E"
7INCL "anyRany"
8INCL "aRb"
9MODE "All classes" from:all
10MODE "Modelling classes" from:all
11EXCL "anyRany"
12EXCL "aRb"