From PostPrep

Code:
  ; $f contains all file text. Replace characters "&", "<", and ">" with non-printing
  ; characters, then split into an array of LINES. Hiding the replaced chars prevents
  ; treating them during the HTML processing
 
  $f=split(join(split(join(split(join(split($f,"&"),$1),"<"),$2),">"),$3),@crlf)