Pushbuttons are "buttons" on the screen to easily and quickly access a function with the mouse.
Pushbuttons can occur at three locations in the R/3 System: in the application toolbar, in the standard toolbar, and in the work area. Therefore, you have to check for the proper location of the standardized functions. In addition, the following general guidelines apply, in particular to non-standardized functions:
You define pushbuttons to appear in the toolbars in the Menu Painter. For these pushbuttons, the system decides automatically if a task-defined function is displayed in the standard toolbar or application toolbar.
You define pushbuttons that appear in the work area of a screen in the Screen Painter. Here you can also add an icon to the pushbutton.
The "Possible entries" pushbutton and the "More" pushbutton on selection screens are further examples for pushbuttons.
Due to accessibility requirements it is not allowed to offer "Hide/Show" functionality for screen areas on pushbuttons. In other words, changes in the layout of screens are not allowed. Use screen changes instead.
Exception: It is allowed to hide or show screen areas below "More"
(show) or "Less" (hide) pushbuttons.
Source: SAP R/3 Style Guide