There is a bug in the pinout for the Olimex USB-Serial-Cable in the section BeagleBone_Black_Serial
Unfortunately, the page is not editable.
The page should be editable once you login. It's not protected. Or just tell me what to change and I'll change it.
You're correct, any pages in the Beagleboard: namespace are indeed protected. I've gone ahead and corrected the error.