The following will create a plugin which will custom palette entries to palette viewer.
Path could be relative or absolute path of dll assembly which contains custom silverlight controls.
Category is a group container to hold a number of controls in palette view.
Most fields are self explanatory.
The class field means the full name of silverlight class.
The code field is optional, and could be used by advanced developer. For example, you can write code as <${tagName:xmlns(System.Windows.Controls.Button)} Content="${cursor}" />