For each released version of your extension, you must create its branch in the SVN repository.

1. In Eclipse, right-click on your project.
2. Select Team > Branch/Tag....
3. Click the Select button (located at the right of the URL field), select the branches folder and click OK.
   
4. Fill in the Copy to URL with your project current version code (for example ...branches/1.0, ...branches/1.1, etc.). Click Next twice.
   
5. In the comment window, enter the project version code (for example, version 1.0, version 1.1, etc). Click Finish.