Which Duif breeds come in Ekster?

Club breed standards describe Ekster for the Modena.

Duif pattern

Ekster

Dark and white in a set arrangement: the Magpie duck's colored cap and back, magpie rabbits and cavies.

2 Duif breeds list Ekster. It is in a club standard for 2 breeds.

Breed	NPA	BDRG
Modena	Standaard (“The color descriptions apply to both Schietti and Gazzi, with the exception of the white on the Gazzi body.”)	Standaard (“Gazzi Blau mit bronze Binden; Gazzi Blau-bronzegehämmert; Gazzi Dunkel-bronzeschildig-gehämmert”)
ModenaGazzi	Standaard (“The color descriptions apply to both Schietti and Gazzi, with the exception of the white on the Gazzi body.”)	No ruling