[TYPO3] How do I disable the RTE for the HTML content type?

[Pieter]

tapio wrote:
> 
> This is weird behavior. I got in one installation that also for content 
> type, which create basic mail form.
> 
> This weird behavior is in the installation, where server uses PHP 5.x.
> 
>> I have been looking at the typoscript and the page/user TSConfig but 
>> it is a mystery up to now...
> 
> Because this should *never* happen, you maybe can't find config for that.

I'm running on PHP 4.x.  Noting special there.
I have seen a thread on this forum (or the dev forum) some time ago 
about this but I can't find it any more.  I thought it had something to 
do with an extension messing things up.  But I don't want to uninstall 
all extensions to find out..

So, anyone: HELP!!  ;-)

Pieter