Colonel (abbreviated Col., Col or COL and pronounced /ˈkɜːrnəl/, similar to "kernel") is a senior military officer rank below the general officer ranks. However, in some small military forces, such as those of Iceland or the Vatican, colonel is the highest rank. It is also used in some police forces and paramilitary organizations. Historically, in the seventeenth, eighteenth and nineteenth centuries, a colonel was typically in charge of a regiment in an army. Modern usage varies greatly.