Board Thread:Game Updates/@comment-26091666-20160624120924/@comment-1637496-20160627135609

Vcharng wrote:

K2B: B(乙) means B-class destroyers (Akizuki-class), since Kasumi K2B is focused on AA and other fleet escort roles. Kasumi got 12.7cm Type 89 guns in her K2B art, which incidentally is Matsu's main armament, a pseudo Akizuki would have received the 10cm Type 98 guns like Fubuki Kai Ni.

In the first place I'm completely unconvinced that those letters refer to destroyer classes with only A/Kou being a most peculiar (and convenient) exception.