The CDC vaccination card is too large to fit in my wallet without getting damaged.
I keep the card with my passport in a plastic sandwich bag on my dining room table.
I might take a picture of my card with my cell phone.
Please remember stores don’t want to be police officers.
Keeping black folks separated from white shoppers was a costly business expense back in the days of Jim Crow.
The reason it is that odd size is because it’s a traditional shot card size, originally intended (back before WW2) to be used with an index card file system in your doctor’s office.