Waypoint Challenges???

After obtaining the LE Strategy Guide for $6, I read that there are some Waypoint Challenges, yet I am unable to find any information about them.
I’ve gone through forums and search engines, and nothing.
Does anyone know what the “Waypoint Challenges” are, and where they are listed?

There is a challage this week for 200 kills with a precision loadout that is under the waypoint challange