Well look at this. This was a stain from upstairs…it apparently looks a bit like High Charity.
It’s a little hard to see.
Here is a enhanced version of it.
Here is the actual High Charity.
https://www.google.com/search?q=high+charity&espv=2&biw=1920&bih=971&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiEjc2az-DJAhUJXh4KHaSSDjkQ_AUIBigB#imgrc=WZ4RIAHCDr5GwM%3A