title: Same tag name for multiple branches
body: <p>I'm currently trying to tag a git projects which same version tag for a release. The project is an extension for an exist product. For backward compatibility with the existing product, we needed to created two different versions of our project. So we created two branches named master (latest version of product) and productX.X (backward compatibility to product version X.X) which contain the different version releases of our product. We're merging the code from the branch master to  the branch productX.X to keep the code in sync.</p>
  
  <p>The number of branches will grow as we need to great a new version of our project when a new version of the product will be released.</p>
  
  <p>Now, I want to release version 1.0.0 of our project for both product versions (latest and X.X). I read that I can use only once tag name for all branches. Is really not possible to tag different branches with the same tag "1.0.0"?</p>
  
  <p>If it isn't possible what would be the good approach?</p>
  
  <p>Alternative approach: Tag the branch "productversionX.X" with a postfix:
  master: 1.0.0
  productversionX.X: 1.0.0-productX.X</p>
  
  <p>I'm currently using Tower as git client and gitlab as git server.</p>
  
  <p>Thanks Patrick</p>