Sometimes a test, or subtest, will include items which are not to be scored.
These are often referred to as "pilot" items, "pretest" items, or "trial" items. They're riding in the test, usually embedded amongst the normal items, just to see how good they are. If they qualify as okay, they might appear in a subsequent version of the test, and be scored (that is, they will move from being unscored items to normal items).
To see how to handle these in Lertap, please refer to this topic.