Top 10 Codes and Ciphers

This is a code where each letter and number is paired with a "tile" according to a tic-tac-toe pattern. It's the most highly documented code. Which symbols stand for what letters, numbers, or other characters may change depending on the user.

This is a code where each letter is represented by a series of beeps. What each arrangement of beeps represent is not subject to change based on its user and can be looked up online.

This is a code where each letter is paired with the number that represents its order in the alphabet. For example, 26 = Z. As such, what each number represents is not subject to change based on its user.

This is a code where each letter, number, and symbol is represented by a series of ones and zeroes. Depending on how it's used, what each arrangement of ones and zeroes represents can be subject to change based on its user. Guides exist that can be looked up.

This is a code where each letter that resembles a non-letter character is replaced by that non-letter character. For example, E's are 3's and S's are $'s. What each character represents is not subject to change based on its user. The list of symbols can be looked up.

This is a code where either letters/numbers are represented by elements on the periodic table or where periodic table elements are represented by letters/numbers. Traditionally, what each element represents is set in stone and not subject to change by its user, but slightly infrequently, users have been known to change it up.

This is a code that has existed for thousands of years, used by the deaf to communicate with one another, and is the oldest code on this list, if we remember that a code refers to any method of communication that swaps one form of visual representation of words and meanings for another. There are multiple types of sign language used in the same way there are many spoken languages, but within those sign languages, what each thing represents is not subject to change based on its user. There is a genre of books and a large section of the internet which can teach you how to use it.

This is a code where each letter is traded for the letter on the exact opposite side of the alphabet. For instance, "azaleas" becomes "zazovzh". What each letter represents is therefore not subject to change based on its user. A guide for it can be looked up.

This is probably the most famous. It involves shifting the alphabet, so that "A" turns into "D", and "H" turns into "K", or other variations.

This refers to any code where the timing of someone's breathing makes up the units of the code. For example, a certain number of seconds spent exhaling could determine the letter that exhale was made to substitute. Many people who study sleep, especially those curious about lucid dreaming, have used variants of it with their subjects. What each unit of the breathing code represents is subject to change based on its user.

This term refers to a code where certain syllables are represented by the letter of the alphabet whose pronunciation sounds like that symbol. For example, "oh, I want to be a success" becomes "OI12BA6S". What each letter, number, or symbol represents may change based on your language and culture, but within your language and culture, they are not subject to change based on the user.