Customizing the metamodel : What you can do with USRPROPS/SAPROPS : Layout capabilities : General layout information
  
General layout information
Users can specify tabs, groups, and the display of controls and their labels in dialogs. To summarize:
Properties are laid out in tabs that are determined by the Chapter command. Pages are automatically added to tabs when properties exceed the space available to display them in a single tab.
The Layout command is used to specify the number of columns that properties are displayed in (in a definition, in a chapter (tab) and in a group), and the positioning of labels of properties (whether they are displayed over the control, directly next to the control, and so on).
Positioning Commands enable exact placement of each control and label for any given page of a definition dialog.