A heterogram is a word, phrase, or sentence in which no letter of the alphabet occurs more than once. The concept appears in Dmitri Borgmann's 1965 book, ', though he uses the term isogram, and in a 1985 article, Borgmann claims to have "launched" the term 'isogram' then. In the 1985 article, he suggests an alternative term, asogram, to avoid confusion with lines of constant value such as contour lines, but continues to use the term "isogram" in the article itself. The term isogram or nonpattern word' has also been used to mean the same thing. 'Isogram' has also been used to mean a string where each letter present is used the same number of times. Multiple terms have been used to describe words where each letter used appears a certain number of times. For example, a word where every featured letter appears twice, like "appeases", might be called a pair isogram, a second-order isogram, or a 2-isogram''. A perfect pangram is an example of a heterogram, with the added restriction that it uses all the letters of the alphabet.
Heterograms can be useful as keys in ciphers, since heterogram sequences of the same length make for simple one-to-one mapping between the symbols. Ten-letter heterograms like PATHFINDER, DUMBWAITER, and BLACKHORSE are commonly used by salespeople of products where the retail price is typically negotiated, such as used cars, jewelry, or antiques. For example, using the PATHFINDER cipher, P represents 1, A represents 2 and so on. The price tag for an item selling for $1200 may also bear the cryptic letters FRR, written on the back or bottom of the tag. A salesman familiar with the PATHFINDER cipher will know that the original cost of the item was $500, so that if the price is negotiated he will not accidentally eliminate all of the 140% margin in the $1200 price shown to prospective buyers. A twelve-letter cipher could be used to indicate months of the year.
Longest examples
In the book , Dmitri Borgmann tries to find the longest such word. The longest one he found was "dermatoglyphics" at 15 letters. He coins several longer hypothetical words, such as "thumbscrew-japingly" and, with the "uttermost limit in the way of verbal creativeness", "pubvexingfjord-schmaltzy". In the book Making the Alphabet Dance, Ross Eckler reports the word "subdermatoglyphic" can be found in Lowell Goldmith's article Chaos: To See a World in a Grain of Sand and a Heaven in a Wild Flower. He also found the name "Melvin Schwarzkopf", a man living in Alton, Illinois, and proposed the name "Emily Jung Schwartzkopf". In an elaborate story, Eckler talked about a group of scientists who name the unavoidable urge to speak in pangrams the "Hjelmqvist-Gryb-Zock-Pfund-Wax syndrome". The longest German heterogram is "Heizölrückstoßabdämpfung" which uses 24 of the 30 letters in the German alphabet. It is closely followed by "Boxkampfjuryschützlinge" and "Zwölftonmusikbücherjagd" with 23 letters. The longest Dutch heterogram is "Exvakbondsjuryzwijgplicht" with 24 of the 27 Dutch letters.
There are hundreds of eleven-letter isograms, over one thousand ten-letter isograms and thousands of such nine-letter words.
Phrases/sentences
Nymphs beg for quick waltz
The big dwarf only jumps.
In French
Lampez un fort whisky!
Plombez vingt fuyards!
In German
"Fix, Schwyz!", quäkt Jürgen blöd vom Paß.
Malitzschkendorf : German city
In Danish
Høj bly gom vandt fræk sexquiz på wc.
In Portuguese
Velho traduz, sim!
In Spanish
Centrifugadlos
Other languages
s, writing systems that only note consonants, and abugidas, where consonant-vowel sequences are written as one symbol, have a naturally high incidence of heterograms.
