On the ELO Guide it Says on one of the Signs othe In And it Should be other Proof: http://prntscr.com/82jgoc
It couldn't fit on the sign, I don't think this matters. Most people understand what they meant. This isn't a bug, this is a letter that couldn't fit on a sign (Spelling) error.
It's a small glitch signs have, if I wrote something on a sign and it was fully entered, the last would be removed anyways.