An analogy for plain text (such as a telegram) might be looking for common words, e.g., "the", "be", "to", "of", ... https://en.wikipedia.org/wiki/Most_common_

An analogy for plain text (such as a telegram) might be looking for common words, e.g., "the", "be", "to", "of", ... https://en.wikipedia.org/wiki/Most_common_words_in_English https://en.wikipedia.org/wiki/Most_common_words_in_English