The document provides examples of different coding logics used to encode letters and words, including:
1) Encoding letters based on their position in the alphabet (next, previous, combinations of next and previous letters).
2) Encoding words by reversing the order of letters or substituting letters in various positions.
3) Encoding letters and words as numbers in different systems.
4) Encoding words by substituting one word for another according to a given code.
5) Mixed coding examples involving both letters and numbers.