title: What is the purpose of Mavens dependency declarations classifier property?
body: <p>I have a pom.xml file and in that i see that their are 3 dependencies referenced for same <code>&lt;artifactId&gt;</code> the difference are in tags </p>
  
  <pre><code>&lt;classifier&gt;sources&lt;/classifier&gt;
  &lt;classifier&gt;javadoc&lt;/classifier&gt;
  </code></pre>
  
  <p>I have deleted the dependencies that had the <code>SOURCES/JAVADOC</code>and only kept one dependency. I tested my application and every thing work fine. </p>
  
  <p>What is the purpose of using this classifier tag? and why i need to duplicate dependencies twice  for adding <code>&lt;classifier&gt;</code> tag with <code>SOURCES/JAVADOC</code> . </p>
  
  <pre><code>&lt;dependency&gt;
     &lt;groupId&gt;oauth.signpost&lt;/groupId&gt;
     &lt;artifactId&gt;signpost-commonshttp4&lt;/artifactId&gt;
     &lt;version&gt;1.2.1.2&lt;/version&gt;
     &lt;type&gt;jar&lt;/type&gt;
     &lt;scope&gt;compile&lt;/scope&gt;
  &lt;/dependency&gt;
    &lt;dependency&gt;
     &lt;groupId&gt;oauth.signpost&lt;/groupId&gt;
     &lt;artifactId&gt;signpost-commonshttp4&lt;/artifactId&gt;
     &lt;version&gt;1.2.1.2&lt;/version&gt;
     &lt;type&gt;jar&lt;/type&gt;
        ***&lt;classifier&gt;javadoc&lt;/classifier&gt;***
     &lt;scope&gt;compile&lt;/scope&gt;
  &lt;/dependency&gt;
  &lt;dependency&gt;
     &lt;groupId&gt;oauth.signpost&lt;/groupId&gt;
     &lt;artifactId&gt;signpost-commonshttp4&lt;/artifactId&gt;
     &lt;version&gt;1.2.1.2&lt;/version&gt;
     &lt;type&gt;jar&lt;/type&gt;
     ***&lt;classifier&gt;sources&lt;/classifier&gt;***
     &lt;scope&gt;compile&lt;/scope&gt;
  &lt;/dependency&gt; 
  </code></pre>