A supplement to The Pocket Oxford-Duden German Dictionary (Oxford University Press, 1997) reports that the governments of Germany, Austria and Switzerland agreed in 1996 to reform the spellings changes resulted in the creation of over one hundred new triple-letter words.
"New German Triple-Letter Words,"
Word Ways: Vol. 36
, Article 13.
Available at: https://digitalcommons.butler.edu/wordways/vol36/iss1/13