Abstract: Disclosed are text processing methods and text processing apparatus in an imaging system which images text characters and associated text functions, and specifically images text underline functions. The imaging system operates to control the appearance of rules for underlining functions, by controlling the offset (O), thickness (T) and gap (G) parameters as a function of user input values and as a function of font size (F.sub.-- size) and typeface parameters (Para.sub.-- 1 and Para.sub.-- 2). A plurality of underline algorithms including a homogeneous algorithm and a composite algorithm are provided for controlling rules.