Source: dist/css/library_boot.css, line 8641
10.3.5.1.1 Vertical padding Level 1
The list of classes used on the body tag
Example
p-y_2 p-y_3:md p-y_4:lg
NOTE:
Combination of classes used as a common decorators.p-y_2 p-y_3:md p-y_4:lg