A coworker was looking for a book the other day that wasn't on the shelf. It was called How to Draw and Paint, Too, by Alexander Murray, and it was published in 1946. He was relieved when the book eventually showed up, but both professionally appalled and personally amused to discover that two pages of illustrations (women in their bathing suits and birthday suits) had been adolescently defaced. These amendments included various arrows and thought bubbles, penned-in nipples, and pixelated-looking pubic hair, along with a slew of sweaty sentiments along the lines of "I want to get laid," "Push here," etc. Today's typo is harder to find than the naughty bits in a drawing book, and perhaps even harder to spot than it is to make, given how online catalog renderings of capital I's and lower-case L's are pretty much identical. (An I and two L's look remarkably like an I and one L, or better yet, two I's and one L.) There were 60 hits on Ilustration* in OhioLINK, and "too many records found for your search" in WorldCat. For an even bigger bang for your buck, try Illl*, which came up 68 times in the former and "too many" times in the latter.
(Fra skisseblokken, by Olav Johan Andreassen, from Wikimedia Commons.)