A user is trying to display Rank (numbers 1, 2, 3, ....) using Rally WSAPI in custom report similar to how they are displayed in UI.
There are three separate items that can be loosely called "Rank" but technically there is no Rank property on Rally artifacts starting with v2.0 of Web Serivces API.
We can think of numbers 1 and 2 as a relative numbering mechanism applied to Backlog items, but they do not correspond to a Rank attribute in WS API. They are specific to the UI, to Backlog page, and cannot be fetched through WS API.
The second example when the word "Rank" is used is the?alpha-numeric DragAndDropRank attribute on Rally artifacts.
It looks like this:
P!!!)gO~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
There is no Rank attribute returned, only DragAndDropRank.
It is technically possible to translate an alpha-numeric DragAndDropRank as a Rank even though this translation is not supported.
See this KnowledgeBase article "How to interpret DragAndDropRank" for details.