#no-unsupported-browser-features

Disallow features that are unsupported by the browsers that you are targeting.

禁止使用浏览器不支持的特性。

.foo { opacity: 1; }
/**    ↑                 
 * Features like this, which is unsupported in IE 8 */

This rule uses doiuse to detect browser support. doiuse itself checks your code against the "Can I use" database.

该规则使用 doiuse 检测浏览器支持情况。doiuse 使用"Can I use"数据库检查你的代码。

This is a good rule to use with "warning"-level severity, because its primary purpose is to warn you that you are using features not all browsers fully support and therefore ought to provide fallbacks. But the warning will continue even if you have a fallback in place (it doesn't know); so you probably do not want this rule to break your build. Instead, consider it a friendly reminder to double-check certain spots for fallbacks.

这是一个很好的规则，它使用 "warning"级别，因为它的主要目的是警告你使用的特性不是所有的浏览器都支持的，因此应该提供兼容支持。但是，即使你有兼容方案，仍然会发出警告；因此你可能不希望该规则打破你的构建。有些人认为它是个友好的提醒，以仔细检查兼容情况。

Bugs and feature requests should be reported on the doiuse issue tracker.

bug 和新特性请发doiuse issue tracker。

#Options

#true

Defaults to the doiuse default, which is "> 1%, last 2 versions, Firefox ESR, Opera 12.1".

默认为 doiuse 的默认值， "> 1%, last 2 versions, Firefox ESR, Opera 12.1"。

The following patterns are considered warnings:

以下模式被认为是个警告：

a { opacity: 0.5; }

As IE8 (which as of this writing had just over 1% global usage) does not support opacity:

因为 IE8(在撰写本文时，全球只有超过 1% 在使用)不支持 opacity：

#Optional secondary options

These options are passed directly to doiuse.

这些选项直接对应 doiuse 的选项。

#browsers: "browserslist string"

A string interpreted by browserslist that designates precisely which browsers you wish to support. Something like "> 1%, last 2 versions, ie >= 8". For details about the syntax (which is the same as when using Autoprefixer, by the way), please read the browserslist documentation.

这是一个 browserslist 解释的字符串，用来精确指定你想支持哪些浏览器。比如 "> 1%, last 2 versions, ie >= 8"。更多详细语法信息(顺便说一下，同使用 Autoprefixer 是一样的)，请阅读the browserslist 文档。

If you set browsers: "last 2 versions, ie >=9" the declaration above is allowed.

如果你设置 browsers: "last 2 versions, ie >=9"，上述声明时允许的。

#ignore: [ "array", "of", "features", "to", "ignore" ]

If you no longer want to be warned about, say, your use of rem, you can use ignore: ["rem"].

如果你不想你使用的 rem 被警告，你可以用 ignore: ["rem"]。