I prepare questions in one chapter and present the answer in another. This involves copying the question text and pasting it into a Results chapter prior to developing the answer. I use Ctrl+C to copy and Ctrl+V to paste (to preserve format and styles).
Today, on pasting, a mysterious small black smiley appeared in the paste. I have seen this on very odd occasions in the past and have simply deleted the smiley. I have done these copy/paste actions hundreds of times without smileys appearing and they do delete easily. I have no idea what caused it to appear and I cannot repeat it with copy/paste of the same text. Maybe this is a random bug or I have inadvertently done something strange.
Original which I copy with Ctrl+C
Example 11.22: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum
Result when I paste with Ctrl+V
Example 11.22☻: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum
Can anyone offer an explanation?