The default Minecraft font supplies Box-drawing characters along with a handful of other glyphs which would greatly increase the expressiveness of ComputerCraft UIs and monitor displays if they were actually supported. Any and all attempts to print most of these glyphs results in nothing but a series of question marks as far as I can tell.

I'm not sure if this was a conscious decision or simply an artifact of how ComputerCraft translates character values to Minecraft font texture coordinates (ChatAllowedCharacters?), but supporting all the glyphs in the Minecraft font would be a welcome addition to ComputerCraft.