The U.S. Army last year published a handbook (pdf) for commanders and other U.S. military personnel who are newly deployed to Germany which describes German customs, protocol and etiquette — as understood by the Army.
It includes a wide variety of interesting and peculiar details, including an introduction to German wine and beer.
“German wine categories are more complicated than German beer categories,” the Army guide says. “There are three types of wine and three colors.”
It also includes advice for how to handle delicate interpersonal situations.
For example, if two persons pledge brotherhood (“Brüderschaft”) over drinks and switch from using the formal you (“Sie”) to the informal you (“du”) and one of them later comes to regret the intimacy — what then?
“If an unhesitating ‘Sie’ is used [by one person] at the next encounter following a Brüderschaft drink, the other person should also revert to using ‘Sie’.”
See “Commanders Guide to German Society, Customs, and Protocol,” USAREUR Pamphlet 360-6, 20 September 2005.