India used in Muscat – Type c15 – 1911-1922 King George V Issue
India used in Muscat – Stamps from the 1911-1922 King George V Issue used in Muscat and cancelled with Type c15 – The Single-Ring Date-Stamp with Large Muscat Letters and Ornamental Device at the Base
India used in Muscat – Type c18 – 1911-1922 King George V Issue
India used in Muscat – Stamps from the 1911-1922 King George V Issue used in Muscat and cancelled with Type c18 – The Single-Ring Date-Stamp with Small Muscat Letters without Ornamental Device at the Base