That's easy to do using placeholder text in the textField. There is a field for that in the IB Inspector if you are using Interface Builder, and STV has parameters you can assign in code for the same thing.
Here's a snippet Tarek posted elsewhere for that:
...
SCPropertyDefinition *propADef = [sampleClassDef propertyDefinitionWithName:@"propA"];
propADef.attributes = [SCTextFieldAttributes attributesWithPlaceholder:@"placeholder for propA"];
...
So, the placeholder data is not 'behind' the table, but is data within the field in the cell itself, and when the field is selected for editing the placeholder disappears and you get the editing cursor in its place.
What you would have displayed then is a Label that says "Show Targets of" and then the placeholder "(Days)" or the like in the textField (as a default). When the cell is selected for editing the (Days) goes away but no problem there, the point is gotten by the user what type of data to enter. If on redisplay (if there is existing data, for example '30') you could catch the cell before displaying using a delegate method and change "Show Targets of [30]" (what would be displayed) to "Show Targets of [30 Days]" [brackets indicate the textField content].
With a little ingenuity and STV's delegate methods and configurability you can make your interface communicate whatever it needs to.
Search on "Placeholder" in this forum for more examples.