twbs/bootstrap — pull request #10940 by smariussorin (2013-10-04 14:04:52+00:00)
Title: Problem with hidden-xs and hidden-sm 

Problem with hidden-xs and hidden-sm because if you have components A with class visible-md , visible-lg and components B with class hidden-xs, hidden-sm between 991 and 961 , components B will be hidden