[Zope] parameters to dtml docs and methods?

Suppose I have two DTML documents and/or methods, method A and method B. Method A Creferences Method B -- Method A: ... <dtml-var name="B"> ... which causes B to be published and it's "value" incorporated into A. Now, suppose there are some variables in A's namespace and further suppose that they are needed in method B. The question is how to pass them from A to B. What is the proper syntax? I find it surprising that I've been able to use Zope extensively without needing to know how to do this. But now I am beginning to write more modular and tigher code and need this mechanism.