26.1 The term "mentally disordered offender" (MDO) is used to describe a person who has a disability or disorder of the mind and who has committed or is suspected of committing a criminal offence. The term covers a range of offences, disorders and disabilities and may be relevant to the decision to prosecute or divert, fitness to plead, and sentencing/disposal. Prison mental health teams should also refer to Chapter 15: Custody for patients in custody. Although "mentally disordered offender" is used in national guidance and legislation-related materials, in practice, reports and correspondence should use person-first language where possible (for example, "a person with mental disorder who is subject to Part 3 of the Mental Health Act 1983").