EXPLAIN diminutive COUNTRIES

Tier A: GB|US|CA
Tier B: FR|DE|ES|PT|IT|DK|SE|CH|NL|NO|IE|FE|AU|NZTier C: RU|AT|PL|RO|HU|CZ|BE|LV|EE|LT|LU|SI|SK|CY|SL|LI|BG |GR|TR|IR|SG|MY|ZA|QA|KW|SA|AE|BR|OM|MT|GITier D: All Others