The typeface Rotis was designed in 1988 by the German Otl Aicher, who died in 1991 in the German village Rotis. This typeface design would have been protected for a period of 25 years, if it had been registered at the Munich design patent office, but by glancing through old Munich design patent records I could not find a registration for it, so that I guess that it had never been registered.
(Typeface designs are not copyrightable in Germany, so this is no issue.)