Very soon, the black bamboo pipe arrived in Si Xi's hands. Si Xi first checked whether the seal on it was intact.
Finding no issues, he immediately opened the bamboo pipe. Inside, instead of text, was a series of numbers, usually divided into three groups, written as [7,3,7], [12,14,8]...
Upon seeing these cipher-like characters, Si Xi carefully distinguished them, then reached out to the shelf next to him and pulled out the fourth book.
The capitalized "four" in front signifies the fourth book, and the numbers [7,3,7] indicate the seventh page, third line, seventh character in that book.
Similarly, [12,14,8] represents the twelfth page, fourteenth line, eighth character in that book.
This cipher has a double safeguard. First, the capital number indicates a specific book, so even if the enemy captures it, they wouldn't understand.
