Errors

(from http://art.thewalters.org/detail/36269/book-of-hours-3/ and https://twitter.com/mcwm/status/927349856544358400)

The first image depicts a little man in the margins, telling the reader that the fragment of text at the bottom of the page belongs in the space to which he points, as the scribe made an error in transcribing¹. The second image depicts a bug that appears in iOS 11, where the autocorrecting keyboard transcribing one's thoughts replaces the letter "i" with a strange sequence of characters².

(from "What Every Programmer Absolutely, Positively Needs to Know About Encodings and Character Sets to Work With Text")

One may think that digital forms represent opportunities for 'perfect' copies, where the data exchanged is exactly the same, but there is still room for error here. Radio communications such as wifi are susceptible to interference, and as such they employ various error correction mechanisms such as Hamming codes that can account for a certain threshold of error. Further, even if each bit of the data is transmitted perfectly, the infrastructures surrounding the data can corrupt the data significantly if the encoding is not also transmitted, as we can see in the image above.