Am 25.09.2015 um 18:12 schrieb robert:

I must define variableByte subclasses in the category. Categories are not part of the namespace nor or symbols looked for there. SO I need programmatic access. I didn't find anything in the documentation, as it is an implementation issue. Could someone knowledgeable point out how I can do this?

ty,
Robert

It is somewhat unclear what you want to achieve.
Categories are simple strings, and "Smalltalk organization" (a SystemOrganizer) keeps the association between classes and categories.
To create a class in a given category, just execute the class creation expression with the proper category, something like this:

| nameOfYourClass nameOfYourCategory |
nameOfYourClass := #MyNewClass.
nameOfYourCategory := 'MyOldCategory'.
Object variableByteSubclass: nameOfYourClass
    instanceVariableNames: ''
    classVariableNames: ''
    poolDictionaries: ''
    category: nameOfYourCategory

Cheers,
Hans-Martin