You use Panels by calling the Panels module using the CALL statement.
The CALL statement must include the panels-parameter-block, which contains all the fields you define when you are working with Panels.
You include the text-buffer and attribute-buffer parameters in the CALL statement, but you need this only if you are writing to, reading from, or scrolling a panel.
When a panel is created or the window is moved or resized, the size of the window might be reduced if one of the specified size cannot be created. This is known as clipping the height and width of the window.