What does PSR-0 stand for?

php

Solution

PSR stands for PHP Standard Recommendation as explained on http://www.php-fig.org/faqs/#what-does-psr-stand-for and here http://www.php-fig.org/psr/

Problem

I know what PSR-0 is, and how, why, where to use it. I've googled for this and looked around stackoverflow related posts, but could not find anything. Even on its official page there's no such definition. So, the question is, what does PSR-0 exactly stand for?

Original source