In the docs, under "Windows programming"|"Graphics and Drawing", you will find the typo I have highlighted in red:
Quote
Raster operations
The RASTERMODE statement sets the current drawing mode. The drawing mode specifies how the colors of the pen and the interior of filled objects are combined with the color already on the display surface. The syntax of RASTERMODE is:
RASTEMODE window, flags
Flags can be any one of the rastermode flags listed in the appendix.
Example:
DEF w as WINDOW
OPENWINDOW w,0,0,640,220,@SIZE|@MINBOX|@MAXBOX,0,"Demo",&main
CENTERWINDOW w
RASTERMODE w, @RMXORPEN