There are at least 10 known manuscripts of Dickens's shorthand, located in 6 archives across the world, as well as 2 private collections. Several manuscripts remain undeciphered, including a letter from the 1850s and a set of shorthand booklets collected by Dickens's shorthand pupil, Arthur Stone.

A former court reporter, “Dickens used shorthand throughout his life but while he was using the system, he was also changing it. So the hooks, lines, circles and squiggles on the page are very hard to decipher.”

Dickens's shorthand has proved extremely difficult to decode, so to this day his texts remain a mystery. In 2021, scholars Dr. Claire Wood and Professor Hugo Bowles put out a call to help solve the Dickens Code —announcing a £300 prize for anyone who could decipher what he was writing. More than 1,000 volunteers came forward, and Shane Braggs, an IT worker from San Jose, California, was able to decipher the most symbols and claimed the prize.

More information is on:

https://www.openculture.com/2022/02/the-code-of-charles-dickens-shorthand-has-been-cracked-by-computer-programmers-solving-a-160-year-old-mystery.html