Mine usually have military style designations. SO is "Simple Orbiter", ORRV stands for "Orbit Rescue and Retrieval Vehicle". But those are usually the common missions with no advanced goal. SO is just for testings things like ORRV. Now, when I get to do fantastic missions with special goals in mind, I name my craft properly. I tried a space station once, name Garfield station. It... didn't go well...