What is a Field Element in pinning

Sorry this is not clearly splet out anywhere. For the purposes of pining

Are we correct in assuming a field element
1/ sides of arena
2/ goals
3/ autoloaders
4/ playing surface

does not include
A/ platform
B/ cubes
C/ other robots
D/ flags
E/ Corner goal

I believe that the platform would be categorized as a field element.

Disregard the previous post. The platform is not considered a field element in this context.

Your interpretation is correct.

However, if a robot is pressed against a cube which is then pressed against the field wall – that IS pinning. The robot is being held stationary against a rigid object.