A hickey (also known as a love bite or kiss mark) is a bruise formed by bursting blood vessels under the skin while biting or sucking the skin. The marks typically last a week or two and can be concealed with makeup or clothing -- or displayed proudly.
Jean Shepherd, one of my literary gods, wrote Wanda Hickey's Night of Golden Memories.
(above) When newspapers were “pasted up” by hand it was common for extraneous strips of paper with text on them, or nothing on them, to get dropped onto what would become the printing plate -- and their images would be printed. (Newspaper article above was written by yours truly for the Brown & White at Lehigh University in 1966 -- when college students used slide rules, cigarettes cost 27 cents a pack and there were no iPads. However, sex had been invented.)
(above) It’s unlikely that you will encounter those problems in a book made with software, a PDF and print on demand -- but there is a 21stcentury version of the hickey.
If you use the "Print Screen" function of your computer, or software such as Snagit, you might accidentally capture an image with a cursor or pointer in it. Be careful.
Top photo from Janek B. via Wikipedia. Thanks.