title: What is this "|" (pipe) means in C#?
body: <p>In the context of Security Cryptography X509Certificates, I've came across this in one of the projects code. </p>
  
  <pre><code>X509Store store = new X509Store("MY", StoreLocation.CurrentUser);
  store.Open(OpenFlags.OpenExistingOnly | OpenFlags.ReadWrite);
  </code></pre>
  
  <p>What is this "|" pipe means here?</p>