Do a search for OWASP and you find 2 references, with the 2nd being this one:
This is great, but what are these 'Guidelines of OWASP'?
Ideally we should should have a series for very explicit and focused 'Guidelines' to answer this question :)
To kickstart this process I created the Guidelines of OWASP page at the OWASP Wiki, so if you have some cycles, please chip in with your views: