A Signal Line Crossover is the most common signal produced by the MACD. First one must consider that the Signal Line is essentially an indicator of an indicator. The Signal Line is calculating the Moving Average of the MACD Line. Therefore the Signal Line lags behind the MACD line.
Autism, PDD-NOS & Asperger's fact sheets | A guide to classification and diagnosis of Autism and Asperger's syndrome. The classification and diagnosis of autism, Aspergers syndrome and other related disorders is constantly changing, and is increasingly the subject of much discussion and dispute.
Asperger disorder was formerly characterized as one distinct autism spectrum disorder (others included autistic disorder, Rett syndrome, childhood disintegrative disorder, and pervasive developmental disorder-not otherwise specified [PDD-NOS]), although Asperger's syndrome was considered to be at the milder, or higher-functioning, range of this spectrum.