Forum OpenACS Q&A: How to specify my own form template and render in xowiki/xotcl

Is there a way to tell xotcl/xowiki which form to use for a specific Form or Template?

There are several versions under packages/acs-templating/resources/forms/ and also I would like to define my own form template.

Same question: Is there a way to specifiy my own renderer? For instance to provide an xml renderer for a form instance or rss?