Users can also convert zerocoins back into basecoins, though in principle this is not necessary: all transactions can be made in terms of zerocoins, if the parties involved support these.
So, just for personal interest - when I had protected my coins (transform these to ‘zerocoins’), how can I transform these coins back to ‘basecoins’ (add to my wallet, make visible in ‘listunspent’, send to regular bitcoin address etc.)?
A lot of the terminology and design have been revamped considerably since the content on zerocash-project.org was written, and it will just confuse you if you try to figure out how the content on that site relates to the content of our current docs.