最高时速100公里，这可能是最慢的一种车次，有很多站。车票一般以6,7,8和9开头，大部分慢车都是绿皮车，没有空调。

Commuter Train
市郊往返列车，通勤列车

These are specially taken by railway staffs, so they are not opened to public passengers.
特指中国铁路内部用于铁路职工上下班往返于居住地和工作地的列车，不对外开放。

L – Temporary
L字头列车：临客，全称“临时旅客列车”
 
This series is in operation only during the peak travel time, such Chinese Spring Festival and the National Holiday. They will not be listed in the official fixed schedule. It is not advised to take this type if you have other options as they are routinely subject to delays.
这个系列的车次仅仅会在客运高峰期的时候出现，比如春节和国庆节。没有固定的发车时间，一般情况下，能坐上别的车，就不会坐临客，因为它们通常都会晚点。

Y – Tourist 
Y字头列车：旅客列车

This type is for the convenience of tourist and their destinations are the popular tourism cities. For example, there are Y-trains departing between Beijing and Qinhuangdao. Its speed is the same as the accommodation type.
这类车次是为游客特设的旅游列车，一般目的地都是热点旅游城市，比如从北京开往秦皇岛的Y字头列车。速度和普快差不多。

S – Suburban 
S字头列车：城郊专运客车

Running at 100km/h as the highest speed, this type is used for communicating city center and the suburban areas. It has no soft seats and sleeper berths as it only travels within short distance in day times. Currently, the S2 series travel between Beijing North Railway Station and the Yanqing County in the northern suburb of the city with stops at Qinghuayuan, Nankou, and Badaling Great Wall.
最高时速100公里，是城区和郊区的往返车。由于路程短，所以没有软座和软卧。目前，北京北发往延庆列车S2线，停车点清华园、南口、八达岭等等。