It is when your diabetes is caused by long term theraputic use of drugs such as in my case corticosteroids specifically for me Prednisolone this is or was generally known as T3E.
"Drugs conferring a high risk of diabetes
Steroids: Steroid drugs can induce a form of iatrogenic Cushing's syndrome, and are probably the most widely used drugs which confer a high risk of diabetes. A Canadian paediatric study found that 0.4% of childhood diabetes was ascribed to medication, and 55 of 56 children in this category were on steroids. Monogenic diabetes was diagnosed in only 0.2% of children.
Anabolic steroids (synthetic androgens mimicking testosterone or dihydrotestosterone) should not be confused with glucocorticoids. Although they have many unwanted effects, diabetes is not among them."
https://www.diapedia.org/other-types-of-diabetes-mellitus/41040851133/drug-induced-diabetes