It's one of Xlib's classes which says "copy the Visual class Type from the parent". Visual Type being "DirectColor", "PsuedoColor", "red_mask", "green_mask", "blue_mask", etc.
http://tronche.com/gui/x/xlib/window/visual-types.html#Visual
CopyFromParent
is a flag saying "copy these values from the, typically the main display window - XOpenDisplay(NULL)
.