I would have a copy of the development that would be validation from my repository. On a live site, I would export (as opposed to checks) tagged versions, and I would name the directory in which this export data is with the tag name "project-v1.4.5", for example. Then I would have a symbolic link to the current active tag. This allows you to revert to an older version much more easily if you find problems after upgrading to a new tag.
If you use SVN, I recommend that you read ( http://svnbook.red-bean.com/ ) sections of the SVN book on fundamental concepts and tags (in the Branching and Merging Section).
SVN , http://svnbook.red-bean.com/en/1.5/svn.advanced.props.special.ignore.html