title: C# Dictionary: Multiple KEYS per Value
body: <p>I'm looking for a way to get multiple <strong>keys</strong> with a single <em>value</em>. Yes, I've already used the search function, but most answers are for the opposite direction (multiple <strong>values</strong> per <em>key</em>), but I want the opposite.</p>
  
  <p>The reasoning behind this is that I want keep multiple Item-IDs (it's for a Bot) per "main" ID, and throwing those multiple IDs into a value of the one is too slow to modify (looking for one value => looping trough all main IDs &amp; getting each value, then checking if that ID exists).</p>
  
  <p><strong>Example</strong></p>
  
  <pre><code>Key 1 =&gt; Value
  Key 2 =&gt; Value
  Key 3 =&gt; Value
  Key 4 =&gt; Value
  Key 5 =&gt; Value 2
  </code></pre>
  
  <p>Looking for Value should return: Key 1-4, not 5</p>
  
  <p>So I'm looking for a way to do that easier - like I said above.</p>
  
  <p>Anyone knows if that's possible and how to do it?
  Thanks in advance.</p>