The ornamental design for a rail, as shown and described.
FIG. 1 is a right end view of a rail showing my new design in an environment of use, the left end view being identical thereto.
FIG. 2 is a front elevation view thereof, the rear elevation view being a mirror image thereto.
FIG. 3 is a top plan view thereof; and,
FIG. 4 is a bottom plan view thereof.
The rail is shown with a symbolic break in its length. The appearance of any portion of the rail between the jagged break lines forms no part of the claimed design.
The broken line areas represent portions of the rail that form no part of the claimed design.