[NTG-context] String single quote in \tt

Hi, I just noticed that in the preprocessing manual, the single quotes are wrong. Look at the output of \starttext \starttyping let a = 'string' ; \stoptyping \mono{ let a = 'string' ;} {\tt let a = 'string' ;} \stoptext The singlequote character is converted into rightquote. This "feature" is also present in plain tex and Latex. rightquote string rightquote does not look good in program listings. Isn't there some way to turn off these intelligent quotes in \tt? Aditya