Hi,
So I just got in game and tested something out here's what you want to do. Follow below.
(leave the 1st line blank)
1
B100
Gold Ore
That's what the sign should look like. If you leave the 1st line blank and when you are done making the sign the game will auto place your name. (Even if your name is too long it may look cut off but i promise it will work)
Hopefully that helps