In fact, the matters Li Youzhi mentioned were merely the tip of the iceberg on the Secret Front.
Why say that?
Because due to the special nature of the Secret Front, whatever actually managed to make it into historical records was bound to be the tip of the iceberg in the first place! According to the *Regulations on Secret Work* formulated by Wu Defeng, the founder of secret communications work, all underground intelligence personnel were strictly forbidden from maintaining lateral connections; they could only communicate through single-line contacts.
Chapter 177