BERLIN — Most people dread a letter from the tax office, so spare a thought for the German man who got 1,700 of them. In an ...

This would show up in an unusual number of repeats. Because more of these letters would have been common German letters like E and N, there would be more repeats than in a random position.

Addressed to an unknown "Gemlich," the letter is typed but signed by Hitler. It will be exhibited at the museum along with a German army typewriter. Visitors will be able to see the original ...