Distinguish between behaviors that are clearly atypical and present across multiple contexts, versus behaviors that are on the borderline of being atypical or rarely occur/occur in only one context. For example, while toe walking may be an example of criterion B1, it may not be sufficient by itself to assign the criterion if there is a physical explanation for the behavior (and thus not clearly atypical) and/or if it occurs only in one context (e.g. at the beach when barefoot in the sand). By contrast, a preoccupation with lawnmowers that involves obsessively drawing lawnmowers, seeking out lawnmowers, and talking about lawnmowers is sufficient to meet criterion B3 even if no other examples exist. This preoccupation is clearly atypical and is present across multiple contexts.