Not-Otherwise Specified (NOS)
Not-otherwise specified (NOS) was used in noting an illness which does not fully meet the criteria of a specific disorder in that category. This sub-classification was used in DSM IV, ICD 9, and ICD 10. For instance, regarding mental disorders, NOS is given when the client meets the general symptoms but are not perceived as clinically significant, the cause of the illness is suspected to be related to a medical condition, or if there is insufficient information to back up the diagnosis. A more specific example is PDD-NOS which was a subtype of autism; it is currently folded into a single diagnosis called Autism Spectrum Disorder.