The key idea of position and orientation at level 6 is that the interactions between loci can be used to solve real problems.
Loci can be used to describe relationships in the real world, for instance the cost of producing a certain number of a product can be described as an equation which can be represented as a graph. Problems involving multiple criteria can be solved by using multiple loci and finding their intersections.
Diagrams give us a way to visualize these loci and enable us to see how different loci intersect both point- and area-wise.
This thread develops from the key idea of position and orientation level 5 by moving from constructing loci to finding points of intersection and areas in common between two loci. There is no further extension of these ideas as far as achievement objectives are concerned. However, the concept of locus occurs from time to time in areas such as calculus.