Perhaps the most versatile tag is the heading tag. Heading tags enable information to be displayed in windows, control entries in the Contents window, control placement of push buttons in a window, and define the shape and size of windows. With IPF, you can specify six levels of headings, :h1 through :h6. For information about default heading levels that start a window and place entries in the table of contents window, see the following topic on Controlling Entries in the Contents Window.