title: Agile - Dealing with changing requirements for already implemented features
body: <p>In a recent meeting with my client, we discovered we missed out on a Detail of User Story, that has already been implemented several iterations before. </p>
  
  <p>The new requirement is not only an additional Feature but changed behaviour. </p>
  
  <p>The original User Story goes like:
  <em>"Can View XYZ"</em></p>
  
  <p>The new request however goes like:
  <em>"Can View XYZ but if B then XYZ must look like ABC"</em></p>
  
  <p>Shall i consider this a Bug or a New User Story, or should i simply reopen the old user Story and edit it to account for the new request?
  What is the "best-practice", what are pros and cons of each approach?</p>