Well... it was of use for me...
I was looking for help in this forums, since this seems to be the only place where there might be a chance of getting answers for such questions. It might happen that somebody else needs to know the same as I did?
Is there anything nastier then finding only questions without answers when searching? That is why I post the answer 
I needed to know this because I'm automating some tasks (transforming POD to Mobi), and I was asked to code them properly in one language (namely Perl). Thanks to
mobiperl, I was able to create mobifiles very soon. But since I have no tool like Calibre or so (Calibre is not Perl) that does everything for me, I need to code it myself. So that is the reason.
Deeper knowledge is always good, isn't it?
Developers of tools for example need to know such things...
Hope I don't offend anybody by posting knowledge here, which I could not find anywhere else?
Regards