    A CSprite is an ordered list of these elements, created with <CTRL-r>.
    Normally, they are packed together in a list and the address of the first is
    passed to routines.

    See ::/Demo/Graphics/SpritePlot.HC, ::/Demo/Graphics/SpritePlot3D.HC,
    ::/Demo/Graphics/SpritePut.HC, ::/Demo/Graphics/SpriteRaw.HC and SpriteMeshEd().

    Be aware that copying SP, IB, or IS entries with the clip results in duplicate
    entries with different nums.  You can manually remove dups by editing with <CTRL
    -t> and setting to the original num.

    See ::/Adam/Gr/GrSpritePlot.HC for how CSprite are stored.