With any parameter, the attribute 'name' will identify the parameter and the attribute 'type' will identify where the parameter gets it's data from . Inside of the parameter element, the element 'value' will contain the value, or the location of the value to be assigned to the parameter. There is a second option element, 'defaultValue', that can contain a raw value to assign if the location of the expected value cannot be located.
For this parameter assignment, a type of 'blockValue' is used. A block value allows you to access data from within a given area in the Technology Explorer. Within a table, a block refers to the row of data from which the action was called, and all displayed data is accessible through its column name specified in the element 'value'.