ThinkPad 200 series
The 200 series was developed as a very compact subnotebook line, in comparison to the 500 series.
While some of the 500 series' models included a docking connector for additional expand-ability, the 200 series did not have such a connector present on any of its models. This was to further reduce the physical dimensions and weight in all areas.
Following the discontinuation of every numerical series ThinkPads, the 200 series was replaced with the S series as its successor.