Numbers read on state radio may be cold war-era method of sending coded messages to spies in South Korea – or an attempt to wage psychological warfare.

A female announcer at the radio station read numbers for two minutes on 24 June and 14 minutes on Friday, according to Seoul’s unification ministry and national intelligence service (NIS). A copy of those comments provided by the ministry included phrases such as “No 35 on Page 459” and “No 55 on Page 913”.

Source: North Korea’s radio broadcast of string of mysterious numbers is possible code