Bangladesh's shift to stainless steel for this denomination in the mid-1990s followed years of problems with earlier cupronickel issues, which suffered accelerated corrosion in the country's humid subtropical climate. The three catalogued varieties — KM#18.1 through 18.3 — reflect minor die modifications made across the production run rather than any policy change.
Bangladesh's shift to stainless steel for this denomination in the mid-1990s followed years of problems with earlier cupronickel issues, which suffered accelerated corrosion in the country's humid subtropical climate. The three catalogued varieties — KM#18.1 through 18.3 — reflect minor die modifications made across the production run rather than any policy change.