Arbortext IsoDraw > User's Reference > Palette Window Toolbox > Callout > Form
  
Form
The form of a callout element is determined by the style that has been assigned. You can change styles and define new styles in the Callout window. This can influence the three individual elements (reference line, text element and text frame).
When you create a new callout element, this element is automatically assigned the style selected at this time in the Callout window.