The routines which draw text all allow you to include escape sequences in the text to be plotted. These are character sequences that are interpreted as instructions to change fonts, draw superscripts and subscripts, draw non-ASCII (e.g. Greek), and so on. All escape sequences start with a number symbol (#).
The following escape sequences are defined:
#u: move up to the superscript position (ended with #d)
#d: move down to subscript position (ended with #u)
#b: backspace (to allow overprinting)
##: number symbol
#+: toggle overline mode
#-: toggle underline mode
#gx: Greek letter corresponding to Roman letter x (see below)
#fn: switch to normal font
#fr: switch to Roman font
#fi: switch to italic font
#fs: switch to script font
#(nnn): Hershey character nnn (1 to 4 decimal digits)
Sections of text can have an underline or overline appended. For example, the string S(freq) is obtained by specifying "#+S#+(#-freq#-)".
Greek letters are obtained by #g followed by a Roman letter. Table 3-3 shows how these letters map into Greek characters.