To create a split button add class .dropdown-toggle-split with your dropdown toggle class And
to add divider between dropdown item use class .dropdown-divider
To create a dropdown with split button use .btn-outline- with your dropdown toggle
To create a flat dropdown use .btn-flat-* with your dropdown-toggle
To create dropdown with you can use .btn-lg for large and .btn-sm for Small with
your .btn class
You can use drop from different direction to use drop from bottom right use
.dropdown-menu-right with your .dropdown-menu. For drop up use
.dropup as a wrapper. For drop right use .dropright as wrapper. For drop left use
.dropleft as a wrapper.
To create a dropdown with groups you can use .dropdown-header for the header of groups and for
separation of group you can use .dropdown-divider.
To create a dropdown with icons use class .dropdown-icon-wrapper with your dropdown and you
class class .dropdown-icon with the default <i> tag.