You get an order of cels from Japan, and they've 
used an oversized CEL to wrap around the 
purchased cels and backing boards?  True, the one 
I got was an image I never would purchase, some 
incomplete image of two hands clasping (like when 
walking), but it was still a CEL!

Then, too, I've gotten notes from vendors, or 
notations listing a cel as belonging to me, on 
the backs of pieces of sketches, both douga and 
genga.  Again, the pictures (the pieces I saw, 
anyway) were nothing spectacular, but it still 
makes me twitchy!