Does anyone know what the letters mean on a 2013 Bennington 20SSINPX? I know the 20 indicates it’s a 20 footer but that’s about it. I have a few guesses like NP seems to indicate it has “no privacy” options and X seems like it does have the “extended rail” often called D rail. But I’m not sure and I have no idea what the I stands for. Any help would be appreciated. Thanks.