There are 5 custom styles that are available to you from within the WYSIWYG editor.

The 5 custom styles that are available to you from within the WYSIWYG editor are: "Button", "Button-Loud", "Button-Large", "Button-Large-Loud", and "more". These styles can be seen and assigned from the "Styles" dropdown in the top right of the WYSIWYG editor.

Each of these styles is a style that is meant to be added to a link.  The safest way to assign these styles (also called "classes") to your links is to click the "link" icon in the WYSIWYG control bar and assign the desired style in the "class" field in the popup. The "class" field is the bottom option of the "General Properties" of the link.

When finished, close the popup window and click "Save" or "Ok" to save your changes.