Are X and Y children of A? That is what many will infer from your diagram. If instead A,X, and Y are merely strings then you have 3 fields that could be within some class name. The question is what are the slashes supposed to imply is where I think 99% of the problem is here.

Given the edits to the question, I'm thinking that the other ideas of this being a binary tree are correct where A, X, and Y are all Nodes of the tree, where A is the Root, with X as its Left Child, Y as its Right Child and the whole structure called a Binary Tree, assuming that there are only 2 children allowed per node. If there can be any number of children then this is a different structure. However, this isn't a Linked List to my mind in the traditional sense as usually a linked list is depicted in linear terms,e.g. A->X->Y so that each node is only pointing at one node, with the anomaly of a doubly-linked list being separate as usually a linked list is a singly-linked list to my mind.

I'm still confused by what that picture is supposed to imply. If someone is at A, do they see X and Y, while at X or Y they only see A? Are all three elements of a class and the diagram isn't useful as there isn't a point in displaying them this way? Would there be other elements that may contain X or Y as the parent node or is it that each node in the tree contains 3 elements like A,X,Y and there isn't any connection among the elements? This is a very confusing picture as this isn't looking like many other graph-like structures I've seen.

So, A is a NodeStation and each of X and Y are Stations. Thus, each is a separate element of the list? Perhaps a better way to display this would be

```
... => X <=> A <=> Y <=...
```

Though even that has some challenges to it, in terms of understanding what is and isn't implied.