Clarifying the relationship/reference capabilities of the Data Module

My current understanding is the following:

1) Using data_node.module one can construct a view with a field that links to a referenced node. This is accomplished by adding a column that contains NIDs which essentially act as node references. I have taken a first step toward documenting how to do this in #898562: How to relate node to data table?.

2) I assume the data_taxonomy.module acts in a manner very similar to that of data_node.module.

3) The patch in issue #617672: CCK Field: Data-row reference would allow the creation of a CCK field that references specific records (rows) of a data table.

Good so far? Please add further documentation!