I tried to time the illumination to get the Lunar X. It is an optical illusion of light and shadow creating the appearance of the letter X. It is only visible for a few hours before the First Quarter Moon. I shot the moon at the beginning of the phase so I had to remove a touch of shadow, but seemed to get it pretty close. Will try next month a couple of hours earlier.

D7500 with 200-500mm lens hand held

large crop, lighting and enhance, add text