The Arabic date ٢٠١٧ (2017) on front of 20-pound notes (B410d) is usually 2-mm tall (top), but a 3-mm tall date (bottom) has been observed on at least one note with prefix ER and serial number in 9000000 range. More examples are requested to determine if this anomaly is a true variety or perhaps a counterfeit.
Courtesy of John Miskell and philanote.