a save system can save anything. you can save the exact location of the player if you want, although i wouldn't advise it.
all a save/load code system does is allow the player to input data (a save code) that the program translates into meaningful data, then output data (after encrypting it) that gives the player a save code.
the big problem is trying to figure out what exactly you want to save and load(player name, lvls, class, etc), and making an encryption system for it.
mainly because its going to be adding another 6-8 digits to your code, unless you are using a high compression technique, and its probably not going to be that important. if you just use inns, you can use 0-9,a-z,A-Z...that gives you 62 inns