It means it's a heavily modified phone. Did you do these mods (S-Off, supervisor) or are you not the original owner?
What happened to get it into this state? Did you try to flash some software, for example? Because all of the security checks that would prevent you flashing something incompatible are turned off, so you need to know what you are doing (e.g. that's a Sprint phone, so flashing another network's firmware could mess things up as the radio hardware is different - and baseband is the radio, which is why I ask).