Menstuff® has information on Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS) is one of the pervasive developmental disorders and autism spectrum disorders.
PDD-NOS is a diagnosis for people who are well-described by the
"PDD" label, but can't be categorized by any other disorder. It is
usually milder than autism and has similar symptoms to autism, with
some symptoms present, and others absent. The boundaries between
PDD-NOS and non-autistic conditions are not fully resolved.