Help needed with Dressage test?

[Pony.Girl15]

In my dressage test it says:

Turn down center line between X&G halt through the walk.

What exactly does this mean?

Should I start walking at X? should I halt at X? should I halt exactly in the middle between X & G or is anywhere between fine?

 

[Cassie J]

Yah, just start walking anywhere between X and G. It could be on X, on G or anywhere in between.