Mode line ~~~~~~~~~ Files should have Emacs and vim mode line comments as the first two lines of the file, which should set ``indent-tabs-mode`` to ``nil``. For new files, use the following, specifying two-space indentation: .. code-block:: cpp /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim: set ts=2 et sw=2 tw=80: */ /* 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 https://mozilla.org/MPL/2.0/. */ Be sure to use the correct ``Mode`` in the first line, don't use ``C++`` in JavaScript files.