From: valends3@gmail.com   
      
   Assuming your setting hasn't bombed itself back to the Bronze Age and then   
   reinvented astronomy from scratch, any "formal" classification system would   
   have to be based on the IAU's recent definition of "planet". So your system   
   wouldn't have Ceresians/   
   Kuplerians/Plutonians, because those bodies aren't true planets. And your   
   system wouldn't have brown dwarfs, because those aren't planets either --   
   they're stars of spectral classes L, T, and Y. Those decisions have already   
   been made, regardless of our    
   feelings about whether Pluto "should" be a planet, or whether a star "should"   
   undergo H to He fusion.   
      
   The bad news is, a system based roughly on the IAU definition would have to   
   concern itself primarily with mass and orbital characteristics. So far as the   
   IAU and any derived systems are concerned, a planet *cannot* be considered   
   "independent of its orbit"   
    it's a contradiction in terms. The good news is, we have a serviceable   
   informal terminology based on those properties already -- "hot Jovian",   
   "super-Earth", etc. -- so all you should need to do is clean that up. See   
   Wikipedia's "List of planet types"    
   article for ideas. Composition is secondary to the IAU definition, so I'd use   
   that as a sub-type. For instance, Jupiter could become "cold Jovian (gas giant   
   class)", Neptune could become "cold Jovian (ice giant class)", 51 Pegasi   
   b...which I guess we    
   have to call "Dimidium" now?...could become "hot Jovian (gas giant class)",   
   etc.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)