[TYPO3] How to create my onw ctypes?

[Johannes Konert]

Hello list-members,
reading all posts about ctypes I cannto find a hint how to write and 
register my own ctypes. Any hint to a docu?

I wanna write a bunch of ctypes and deactivate all others for a specific 
part of the pagetree. Configuration can be done via TCEFORM AFAIK, but 
how to write an extension that creates new ctypes?
Where are they registered?
How to tell Typo the way the input fields, lists, descriptions, acor 
point-selection, helper-texts have to be displayed in the backend?

(Of course I could write an extension, serving the content via ctype 
plugin, but this is not the convenient way, because the texts etc should 
be stored in normal tt_content and easily editable via backend and 
searchable etc...or is there a way to do this with a normal plugin as well?)

Thank you for some hints. There might be a documentation out there 
allready, but I haven'T found it yet.
Thanks in advance
Regards
Johannes
..still a newbie to TYPO3