I came across this quaint code system in Edward Granville Browne’s book A Year Amongst The Persians (1893). The English traveler discovered it whilst visiting Yezd, in central Iran. The written form of the system resembles both runes and Morse code.
Many people are aware of the abjad system of Arabic. As well as being a generic term for alphabets (like the common forms of Arabic and Persian) which show no vowels, it is also the name of a counting system, taken from the first “word” of an Arabic pangram. In the traditional system, the letters in this pangram are assigned numbers in order: alef to tah taking 1 to 9, yeh to sad taking 10 to 90, qaf to zah taking 100 to 900, and ghain taking 1000.
The Yezdi system works differently, and assigns a pair of numbers to each letter. First, each “word” is numbered. Here is the pangram (with Persian pronunciation) showing the order and grouping of letters.
Next, within each word individual letters are numbered 1 to 3 or 1 to 4. To encode for example feh, we need word number 4 and letter number 3. This can be communicated in signal fashion, where the pangram word number is given a double knock, and the letter number within that word is given a single knock. To transmit letter feh, we would knock the pattern
: : : : - - -
A Written Example
This is the example given in Browne’s book, together with a written version of the code. First the Persian:
What is thy name?
In the version called “cypress writing”, the right-hand branches show the pangram word number, and the left-hand branches show the letter number within that word. Note how the Persian tcheh is substituted for the nearest equivalent in Arabic.