Wearing a 34A bra when you are actually a 26D is sister sizing, but from experience

EPBOT: Everything You Never Knew You Needed To Know About Bras

Bra Sister Sizes + Sister Size Chart

EPBOT: Everything You Never Knew You Needed To Know About Bras

Bra Sister Sizes Explained – Brastop US

Sister Sizes: The Bra Secret Every Person Should Know – Sister

Sister Sizes: The Bra Secret Every Person Should Know – Sister

Bra Sister Sizes + Sister Size Chart

Bra Sister Sizes + Sister Size Chart

Bra Sizing Sister Size Tips Chart Brands ThirdLove

Is 34C the same as 32D in bra size? - Quora