I did not understand how to change the small drop down arrow in the navigation menu bar until @Jaklund posted a short video. It uses the custom class .caret to modify the size. You set it to 0 margin it is gone.
I looked at the Bootstrap 3 CSS Classes Desk Reference and there it is next to a laundry list of other classes. The custom classes for Blocs are really crucial to make all the necessary changes one likes to have.
How can I find more in depth information about these classes?
Are the any other links/tutorial etc explaining the different function of these classes.