[TYPO3] All environment-safe server and environment variables?

[Bing Du]

Curt Grimley wrote:

> One way to see the variables is make yourself a phpinfo.php script on 
> your server as simple as this:
> 
> <?php
> phpinfo();
> ?>
> 
> Run that, scroll down to "Apache Environment" and also "PHP Variables" 
> sections, you will find interesting information there.
> 
> Not sure about 'environment-safe'... but as to what they are, I'm sure 
> you can find info on apache.org.
> 
> ~Curt

Thanks, Curt.  I know phpinfo.php.  Yeah, it lists the PHP variables. 
I think my question was not very clear.   The examples of the variables 
that can be given to the t3lib_div::getIndpEnv function provided in the 
TYPO3 Core APIs document are like TYPO3_SITE_URL, TYPO3_REQUEST_URL, 
TYPO3_SSL.  I guess what I was asking was, are they the only three typo3 
specific variables?  If not, where and how can I find others?

Thanks,

Bing