Arbortext Command Language > set Command Options > set showspaces
  
set showspaces
set showspaces= { on | off}
This command controls the appearance of space and tab characters. When showspaces is on, Arbortext Editor displays a character for each space or tab in text content:
Spaces: a small dot above the baseline
No break spaces: the degree/ring character (°)
Tabs: a right arrow (⇒)
The default is off.