Relative-Offset
When this style is set, the LINE and COLUMN coordinates of controls displayed on a Tab-Control with the 
Allow-Container style are relative to the Tab-Control area. If the style is not set, then coordinates are relative to the window area.
 
Example - Define a tab-control with relative-offset style
screen section. ...   03 screen-1-tc-1 Tab-Control      line 2.8      column 25.7      size 34.6 cells       lines 28.9 cells       help-id 1036      id 10      background-low      bold      allow-container      relative-offset      .  |