Hassanal Bolkiah assumed the sultanate in 1967 following his father Omar Ali Saifuddien III's abdication, and early official portraiture on Bruneian coinage omitted the regnal numeral — a detail corrected in later issues once the style of his titulature was standardized. The distinction between types with and without the 'I' suffix is subtle enough that the two are frequently conflated in collections assembled without reference to KM#18a specifically.
Hassanal Bolkiah assumed the sultanate in 1967 following his father Omar Ali Saifuddien III's abdication, and early official portraiture on Bruneian coinage omitted the regnal numeral — a detail corrected in later issues once the style of his titulature was standardized. The distinction between types with and without the 'I' suffix is subtle enough that the two are frequently conflated in collections assembled without reference to KM#18a specifically.