Sorry, too much haste.

For Arial,9,'N' ( standard VFP ),

? TXTWIDTH(CHR(9),'Arial',9,'N')=TXTWIDTH(SPACE(3),'Arial',9,'N')

CHR(9) is on Text,in fact Maxlenght is bind to Text.

CHR(9) is not converted to 3 spaces, it have a specific
space for any font, and TEXTWIDTH support this.