The best header (license and JSHint options) I know of for Mozilla Add-on SDK code.

header.js

/*! This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/*jshint forin:true, noarg:true, noempty:true, eqeqeq:true, bitwise:true,
strict:true, undef:true, unused:true, curly:true, browser:true, white:true,
moz:true, esnext:false, indent:2, maxerr:50, devel:true, node:true, boss:true,
globalstrict:true, nomen:false, newcap:false */

"use strict";