N.J. Stat. Ann. § 51:11-11

The superintendent shall issue license tags and identification cards to every licensee. The license tags shall be plainly and conspicuously exhibited on and shall be firmly attached to the left side of any vehicle used by the licensee to transport soil amendments. The identification cards shall be carried on the person of the licensee at all times and shall be exhibited upon request to any weights and measures official. The superintendent may, in addition, require any other identification or credentials he deems necessary.