ICD-11 classes
21 Symptoms, signs or clinical findings, not elsewhere...
Mental or behavioural symptoms, signs or clinical findings
MB25 — Symptoms or signs involving form of thought
MB25.2 — Neologisms

ICD-11 MB25.2 — Neologisms

The invention of new words that have meaning only to the person using them. May also include the use of existing words in ways that are inconsistent with their common meaning.

The diagnosis includes nothing.

The diagnosis excludes nothing.

It has no clarifying diagnoses.