How does Clintrial use subset keys and subset values in Central Designer?

When subsets are used in the Clintrial application, one item in a panel is designated as the subset key item. The value of the subset key item determines the record in which to store a set of subset data.

In the CIS data mappings generated by the Central Designer application:

The panel (CTPanel) data mapping identifies the subset key item. The Central Designer application obtains the name of the subset key item from the name of a custom dimension defined on a data set. An unmapped item with the name of the custom dimension is added to the data mappings for the panel and becomes a column in the panel when synchronized to the Clintrial application.
The item (CTItem) data mappings hold the subset value (the value of the subset key item). The Central Designer application obtains the subset value from the custom dimension label that you associate with an item when you map it to a data series within the data set.