title: In Section 508, must a Link Annotation be the first thing inside a Link structure?
body: <p>I am using the PAC PDF Accessibility Checker to analyze some PDFs. I am confused as to whether this is truly an error (as reported by this software) or whether the software possibly has a bug.</p>
  
  <p>This deals with a Link structure. In examining a document which does not report an error. I see the structure reported by the tool is this:</p>
  
  <p><a href="https://i.stack.imgur.com/O7MiY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/O7MiY.png" alt="enter image description here"></a></p>
  
  <p>There is a Link structure element which has inside of it a Link Annotation followed by a Span which contains the text "deductible". </p>
  
  <p>Another PDF has this which is reported as an error that "Link Annotation is not nested inside a Link structure element":</p>
  
  <p><a href="https://i.stack.imgur.com/KKCm7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KKCm7.png" alt="enter image description here"></a></p>
  
  <p>The only real difference in these two is that the Span is <em>before</em> the Link Annotation <em>but</em> there is no question that the Link Annotation in the second example is nested <em>inside</em> the Link structure.</p>
  
  <p><a href="https://i.stack.imgur.com/oS4Yp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oS4Yp.png" alt="enter image description here"></a></p>
  
  <p>I believe this second structure is valid and should not be an error as reported but I am not sure. Question is ... does anyone know? </p>
  
  <p>Must a Link Annotation be the first thing inside a Link structure or ? </p>
  
  <p><strong>Update</strong></p>
  
  <p>Using Adobe Tag viewer as suggested in one answer shows that it is clearly nested inside:</p>
  
  <p><a href="https://i.stack.imgur.com/70d4p.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/70d4p.png" alt="enter image description here"></a></p>