---
title: additive-symbols
slug: Web/CSS/@counter-style/additive-symbols
translation_of: Web/CSS/@counter-style/additive-symbols
---
<div>{{CSSRef}}</div>

<p><code><strong>additive-symbols</strong> 描述符</code> 定义符号，用于值可累积的可数的 {{cssxref('system')}}的项 。 <code>additive-symbols定义累积的的元组（tuples）,每个元组项都包含一个符号和一个非负整数的权重。</code>additive system被用于构造<a href="http://en.wikipedia.org/wiki/Sign-value_notation">sign-value numbering</a> （符号-值，指数字的值就是是符号加在一起的值）系统，比如 罗马数字。</p>

<pre class="brush: css no-line-numbers">additive-symbols: 3 "0";
additive-symbols: 3 "0", 2 "\2E\20";
additive-symbols: 3 "0", 2 url(symbol.png);</pre>

<p>当系统描述符是循环，数字，拼音，象征，或固定的时候，使用 {{cssxref('symbols')}}代替<code>additive-symbols</code></p>

<p>{{cssinfo}}</p>

<h2 id="语法">语法</h2>

<h3 id="Formal_syntax">Formal syntax</h3>

{{csssyntax}}

<h2 id="示例">示例</h2>

<h3 id="HTML">HTML</h3>

<pre class="html prettyprint" id="htmlOutput">&lt;ul class="list"&gt;
   &lt;li&gt;One&lt;/li&gt;
   &lt;li&gt;Two&lt;/li&gt;
   &lt;li&gt;Three&lt;/li&gt;
   &lt;li&gt;Four&lt;/li&gt;
   &lt;li&gt;Five&lt;/li&gt;
&lt;/ul&gt;</pre>

<h3 id="CSS">CSS</h3>

<pre class="brush: css">@counter-style additive-symbols-example {
  system: additive;
  additive-symbols:V 5, IV 4, I 1;
}
.list {
  list-style: additive-symbols-example;
}</pre>

<h3 id="结果">结果</h3>

<p>{{ EmbedLiveSample('示例') }}</p>

<h2 id="Specifications" name="Specifications">规范</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>{{SpecName('CSS3 Counter Styles', '#counter-style-symbols', 'additive-symbols')}}</td>
   <td>{{Spec2('CSS3 Counter Styles')}}</td>
   <td>初次定义</td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>



<p>{{Compat("css.at-rules.counter-style.additive-symbols")}}</p>

<h2 id="相关链接">相关链接</h2>

<ul>
 <li>{{Cssxref("list-style")}}, {{Cssxref("list-style-image")}}, {{Cssxref("list-style-position")}}</li>
 <li>The {{cssxref("symbols", "symbols()")}}, functional notation is used for creating anonymous counter styles.</li>
</ul>