From the publisher:

4 Stripes for the banderole bar.

Before you start the game, lay out the four strips next to each other in any order and orientation in a single line above the banderole bar. As a result of this placement, the strips can be upside down.

Whenever a player places a building tile on a space with a banderole, instead of removing that banderole from the game, they instead place it on first empty space from the left or from the right on the bonus strip. If the space they are placing it on has an icon that player receives the corresponding bonus, either a ware (fish, herb, chicken, grapes), a coin, a bread, a fountain card or a 3-point victory point card.

As usual, the player gets to advance 1 space on the banderole bar.

For more information, please refer to the BGG listing.