A custom control is a collection of controls that can be added to multiple XPages. When you update a custom control, every XPage that uses the custom control is automatically updated.
For this exercise, you want to put "header" information (a boilerplate) at the top of every XPage. Rather than entering or copying the design multiple times, you design once with a custom control.
Creating a custom control
The custom control interface is similar to the XPages interface including an edit area, properties area, controls palette, and data palette.
Using a custom control
Custom controls can be used on XPages and other custom controls.