I'm pretty sure that someone has noticed this, but when I switched from forced unicode enabled to disabled after typing text on a sign, the text just bled, or overflowed, in technical terms, off of the sign. The image below shows a sign with text that I had typed out in with force unicode enabled, showing what it looks like after I had disabled said option.

Edit: I then tried doing it with written books as well, but I haven't included a screenshot of it, due to the fact that they just cut off at the end. I also added an image of the same sign with unicode turned on.

Edit #2: I forgot to mention this, but it appears to be any game mode, or at least affects both survival mode and creative mode.

Edit #3: Also affects hanging signs. 

Side Glitch 1: Overflowing text is only visible from the side that contains said text. (See video below)