[development] Hook_elements?

[Richard Morse]

Hi! Is there any good documentation about how to implement your own  
elements through hook_elements()? I must confess that the example  
file provided on api.drupal.org doesn't seem entirely clear to me --  
why do I want or not want '#input' to be true, when does '#process'  
get called (I tried to create my own element, but '#process' never  
got called), do I have to register the theme function via hook_theme 
(), what internal keys to the formapi should I be messing with, what  
are the standards for themeable elements -- is there any place I can  
go to find out these kinds of things?

Thanks,
Ricky

The information transmitted in this electronic communication is intended only
for the person or entity to whom it is addressed and may contain confidential
and/or privileged material. Any review, retransmission, dissemination or other
use of or taking of any action in reliance upon this information by persons or
entities other than the intended recipient is prohibited. If you received this
information in error, please contact the Compliance HelpLine at 800-856-1983 and
properly dispose of this information.