The Greek numbers from 1 to 999 are properly marked using the Greek numeral sign (κεραία, keraía). This appears in Unicode as greek numeral signʹ (U+0374), which is anomalous on Wiktionary and improperly links as ʹ (modifier letter prime, U+02B9). This entry is encoded using the modern Greek accent mark (τόνος, tónos), which appears in Unicode as tonos΄ (U+0384). Other marks are also sometimes used.