Accurate interpretation of electroencephalograms requires knowledge and experience with a wide range of findings. Misinterpretation is common and may result from insufficient inexperience, incomplete training, or simply human error. However, misinterpretation may also arise from the relative rarity of some findings, and also from the evolution and necessary change in our understanding of the significance of these findings. One of the most common sources of reader error is in dealing with patterns that have some hallmarks of abnormalities but are actually normal findings. We refer to these findings as variants, or “patterns of unclear significance.” This chapter reviews several of the common and uncommon patterns (fast or slow alpha variant, alpha squeak, rhythmic midtemporal theta bursts of drowsiness, midline theta rhythm, subclinical rhythmic electrographic discharge in adults, 14- and 6-Hz positive bursts, 6-Hz spike-and-wave bursts, benign sporadic sleep spikes, wickets, frontal arousal rhythm), emphasizing characteristics that can optimize interpretation.