20.7 Like some FIRST DECLENSION nouns, e.g. τιμή, τιμῆς, ἡ, second declension nouns can have a persistent accent on the ultima of all inflected forms. When this happens, a CIRCUMFLEX is used on the genitive and dative, singular and plural (i.e., a “circumflex belt”); an ACUTE accent falls on the nominative and accusative, singular and plural.
Unlike the first declension, the accent of the GENITIVE PLURAL of second declension nouns is not inevitably drawn to the ultima.