Typography
Let's talk about some of the changes to typography in this version of Bootstrap.
Font Classes
font-weight-*nowfw-*font-size-*nowfs-*- Display 5,6
 
Some of the classes have been renamed, so for example instead the font-weight class has been abbreviated to fw.
There's a new font size class that matches the sizes of headlines.
There are also two new display classes for larger headlines that are numbered five and six. They are smaller than the first four sizes, but do give you some additional flexibility.
Weight/Styles
- 
fw-{WGT}- WGT: 
lighterlightnormalboldbolder 
 - WGT: 
 - 
fst-{STL}- STL: 
italicnormal 
 - STL: 
 
Line Height
lh-{HGT}- HGT: 
1smbaselg 
- HGT: 
 
There's a few line height styles that let you quickly control the space between lines of text. I think they're a little hard to remember.
Miscellaneous
- No 
text-justify - Links underlined
 text-monospacenowfont-monospace- Removed 
text-hide list-group-numbered
The text-justify class has been removed I didn't really like full justification, so I like this change.
Links are now underlined by default...not just on hover like before.
text-monospace is now called font-monospace
This is pretty minor, but you should be aware that the text-hide class has been removed, but you can easily use one of the display classes, so it's not really necessary.
In list groups, there is now an option to create numbered list groups with a new class.