I don't know if this has been posted yet, I just tried a couple of minutes ago, and did not find my thread.
Hi, yes it has, and was answered by Foundinrolls. But sometimes it does seem it has disappeared. I agree with his comment that it is damage. Notice that even though it has the appearance of underlying extra "D"'s upper rt. curve, the rest of what would be that "D" does not appear and it should as it would be the same size as the original "D". Since all of the effect is within the first "D", it could only be damage. If it were a RPM you would see the rest of the underlying "D" to the left of the original D. Hope that makes sense. But you are training the eyes to see the real thing when it comes about. Welcome to the forum, If I haven't already! Jim