title: private const vs public readonly
body: <p>I got three class files where in constant is declared as </p>
  
  <pre><code>private const string PAGE_SIZE = "PageSize";
  </code></pre>
  
  <p>Is it good to move this to new file to hold all common constants declared as </p>
  
  <pre><code>public readonly string PageSize = "PageSize";
  </code></pre>
  
  <p>What are the pros and cons for this?</p>