title: Value of BlipExtension Schema URI: "28A0092B-C50C-407e-A947-70E740481C1C"
body: <p><strong>Question</strong></p>
  
  <p>The class <code>DocumentFormat.OpenXml.Drawing.BlipExtension</code> has a property called <code>Uri</code>.  In numerous examples I've seen the value <code>28A0092B-C50C-407e-A947-70E740481C1C</code> used; but never found what this value is / whether it's important, or if it's arbitrary and only prevalent because of people copy-pasting from existing sample code.</p>
  
  <p>Does anyone know what the relevance of this GUID value is?</p>
  
  <p><strong>Background</strong></p>
  
  <p>I've been fixing a bug in a legacy application, and have been refactoring at the same time to remove some of the code's spaghettification.</p>
  
  <p>Whilst doing this I spotted a few hardcoded values;
  any image inserted into the document is given the name <code>Koala.jpg</code>.  The system has nothing to do with Koalas; implying that the person had simply copy-pasted some code and not thought about the context / meaning of these values.
  Another hardcoded value is the Uri for a BlipExtension: <code>28A0092B-C50C-407e-A947-70E740481C1C</code>.
  I wanted to determine whether this GUID has any particular meaning, or if it's just a unique value.  Googling shows this value used in lots of sample code, but so far I've found no explanation of what it is.  Example results below.</p>
  
  <ul>
  <li><a href="https://technet.microsoft.com/pl-PL/library/bb497430(v=office.14).aspx?cs-save-lang=1&amp;cs-lang=vb" rel="nofollow noreferrer">https://technet.microsoft.com/pl-PL/library/bb497430(v=office.14).aspx?cs-save-lang=1&amp;cs-lang=vb</a> (with Koala.jpg)</li>
  <li><a href="https://msdn.microsoft.com/en-us/library/office/bb497430.aspx" rel="nofollow noreferrer">https://msdn.microsoft.com/en-us/library/office/bb497430.aspx</a></li>
  <li><a href="https://stackoverflow.com/questions/9155987/insert-an-image-into-word-document-using-open-xml-and-c-sharp">Insert an image into word document using open xml and C#</a></li>
  </ul>
  
  <p>Looking at the BlipExtension documentation doesn't give much info on how I could find out what this GUID is / what schema this refers to.
  <a href="https://msdn.microsoft.com/en-us/library/documentformat.openxml.drawing.blipextension.uri(v=office.14).aspx" rel="nofollow noreferrer">https://msdn.microsoft.com/en-us/library/documentformat.openxml.drawing.blipextension.uri(v=office.14).aspx</a></p>