title: How much is maximum value of og:ttl of facebook sharing?
body: <p>Context: Share a webpage on facebook wall of users</p>
  
  <ul>
  <li><p>Share a webpage with a image</p></li>
  <li><p>After some minutes, the image is deleted from my website</p></li>
  <li><p>About some days (7 or use og:ttl), the webpage is re-scraped. In the sharing post on facebook wall, the image is lost.</p></li>
  <li><p>Hope that the image of the sharing post will never be lost. Thus, og:ttl should be set very-large value.</p></li>
  </ul>
  
  <p>At <a href="https://developers.facebook.com/docs/sharing/opengraph/object-properties?locale=en" rel="nofollow noreferrer">https://developers.facebook.com/docs/sharing/opengraph/object-properties?locale=en</a>, og:ttl has minimum value 345600 seconds (4 days). But maximum value is not given.</p>
  
  <ol>
  <li><p>How much is maximum allowed value of og:ttl of facebook sharing? Could I set very-large value (3153600000 ~ 100 years ~ forever) for the tag?</p></li>
  <li><p>In case that the very-large value is allowed, Whether is the webpage still re-scraped but the time is not expired?</p></li>
  </ol>