If you ever decide to create a choice column within a SharePoint list (Image below) you will want to understand how Appit interprets a given input for it.

In this example I've selected checkboxes. When we appify this list and create the new K2 forms this is the end result:

That is a Choice control and Appit has associated it with the Choice column of the SharePoint list. The thing to note about that is this; the control's value is passed as an array.

What this implies is that even though we can select multiple checkboxes only one value gets passed. In the image above the value getting passed would look something like {1,0,0} meaning that checkbox 1 is selected while 2 and 3 are not. If Checkboxes 1 and 2 were selected but not 3 the array would be {1,2,0}. What this means is that if you structure any rules to fire based off of the specific choice, you will have to configure a rule for every possible array value i.e. every combination of choices.