post #996918

X-ray is a type of invisible electromagnetic radiation used to produce a black and white image of a creature's internal skeletal structure.

Not to be confused or used interchangeably with internal.

Internal is for an image or animation depicting penetration, vore, etc which feature either translucent body parts, which allow the act to be viewed from inside the character, or additional image/images to the primary image showing a cutaway image, visually depicting exactly what is going on inside the character's body.