Confused about Semen Analysis

My husband had his Semen Analysis done last Friday. When we got the results from the lab, everything was in "normal range". Our only concern was the Morphology. In the spot where the number should be it had the letter "S". We asked someone from the lab to explain what the "S" stood for and they said we would have to contact our doctor who ordered the test. I am so worried and so is my husband. Has anyone every had the same results for the Morphology?