[opencms-dev] chapters about creating forms?

[tol]

In CHAPTER 11. BACKOFFICE MODULES (page 75) of the 
opencms-documentation-pdf  I read the following lines:
"[...] Those dialogs are made the same way than a normal form in the 
OpenCms (see the chapters about creating forms in OpenCms). There are 
some formalities to comply with when writing those forms: [...]"

Perhaps I have some tomatoes on my eyes, but where is that chapter about 
forms?? Is it within this PDF or an online-doc-module?

Tol