The ornamental design for a banner, as shown and described.
FIG. 1 is a front view of a banner; and,
FIG. 2 is a back view, thereof.
The broken lines in the drawings depicting a frill around the solid line perimeter of the banner and the broken lines including the area within the five star features drawn in the center stripe of the banner represent unclaimed environmental structures and form no part of the claimed design. The parallel horizontal stripes on the upper and bottom portions of the drawing indicate solid stripes that are red in color and do not represent parallel lines. The center stripe is filled with diagonal lines that indicate the color blue and do not represent diagonal lines on the flag. The stripes between the red stripes and the blue stripes are white stripes. The banner includes five stripes of color in the following order from top to bottom: a red stripe, a white stripe, a blue stripe that includes five stars with unclaimed environmental material, a white stripe, and then a red stripe.
The banner is flat and planar. Depth forms no part of the claimed design.