You must be compliant with the entire section but that does not mean you have to have each type of barrier in order to be compliant. This section is written in order to cover all the various types of barriers that could be used. For instance; R4501.17.1.6 is if you want to utilize a chain link fence , R4501.17.1.7 is if you want to have a fence with diagonal members. These codes were put in to help ensure the barrier is not climbable which is the one item that was left out of the description of the proposed pool barrier.
I dislike this type of code question. I do not believe there is enough to go by to answer. However, Michael's attempt is good. They could be using a type of field fencing for all we know. Also beyond the perimeter, the barrier between the pool and house needs to be addressed.
