On Long Island, it's pretty much the same as a yard/garage/estate sale.

Except at a tag sale the price goes down each succeeding day.

To me a tag sale is where the regular price is posted on the item & a small tag states a discount price. Also the tags can be color coded & each color has a different percentage discount off the regular price. So a red tag can be like 10% off regular price, green 15%, yellow 20% & so on.

Born & raised in New England, so a tag sale is a yard sale and things are open to haggling unless it's one of your must haves and then you pay the price they're asking. Where my mom lives, they hold a town-wide tag sale every year.

I'm from CT, and when I go to visit, I see "tag sales", now in PA, I see "yard" or "garage" sales.