National Cartoonists Society
The National Cartoonists Society is the world's largest and most prestigious organization of professional cartoonists. The primary purposes of the NCS are to advance the ideals and standards of professional cartooning in its many forms, to promote and foster a social, cultural and intellectual interchange among professional cartoonists of all types, and to stimulate and encourage interest in and acceptance of the art of cartooning by aspiring cartoonists, students and the general public. The Society's offices are located in Winter Park, Florida. In addition, the NCS has chartered 16 regional chapters throughout the United States and one in Canada.
I like the White Galaxy Marker very much for writing on dark paper, and I have used it to cover another color when I needed to disguise a mistake or simply change effect.
For example, I bought an ornament with name SCARLETT spelled on it and by covering the last 't', I was able to give this to someone with a cat named SCARLET.
If color to be covered is a paint or other pen color, that can make the other color "stain" the white marker tip. This can be avoided if one is sure first color is dry before trying to cover it with white.