Well.... "If you can read this, you're hired.(Null)" You might want to pad that out with spaces or make it "you are" so people don't think your name is Null or that the Null is the starting salary. At least it's not EBCDIC.
So your premise is that this isn't just text and the entire shirt is a string? I think I win this one. Although, if you can make a whole shirt out of just one string then I will concede the point.