Functioning Labels and Autism | Neurodiversity A functioning label is any descriptor used to categorize autistic people on a linear spectrum based on how well they can pass as a non-autistic person. Examples of functioning labels include: Severity levels 1, 2, and 3 High Functioning / Asperger's Syndrome ("aspie") / Severity Level 1 Low Functioning / Kanner's Syndrome / Severity Level 3