twitter/bootstrap — pull request #2674 by sethaldridge (2012-03-19 02:16:31+00:00)
Title: Grid Update: Added .insetX columns for better mobile controle 

I created the opposite of the .offsetX class called .insetX

I updated the mixin.less section to auto create the classes based off the existing pattern and updated the docs with a working example.

This is helpful when you need the ability to display content on a mobile or tablet device one way and differently for larger screens.

You use .inset similar to .offset except it pulls the column to the left.