What is a free-form sub-page?

In CollabNet TeamForge, a free-form sub-page is a page that doesn't show up in the project page hierarchy in the left navigation bar.

As the top-level pages must be visible in the left navigation bar, you can only make sub-pages as free-form pages.

There may be some content within your project, for example, specific wiki pages/documents/internal release plans, that you want to share with your team members in a page, but do not want to provide the page title on the left navigation bar. You can create a free-form sub-page and add links from there, or add the relevant content in to the free-form sub-page itself.

In other words, creating free-form sub-pages is a way of sharing information, without cluttering the left navigation bar.