Corona rapid test only slightly positive - what does that mean?

What does it mean when the T-line of a corona test only appears very pale? Is the result still positive? The interpretation of rapid test results is not always clear. Sometimes the test does not do what it should. For example, it can happen that the T-line only appears very pale. However, as it is the decisive indicator for determining whether a test is positive, such a result understandably causes confusion. Moreover, the instructions for the rapid tests do not mention anything about this scenario. There, the lines are usually shown in bright red.