Old versions of Subversion required you to remember the revision, but since 2009 and version 1.6, that is no longer the case.

A modern SVN workflow can easily look like this:

  svn co https://svn.example.com/myproject/trunk .
  svn copy . ^/branches/feature_branch -m 'Created feature branch'
  svn switch ^/branches/feature_branch
  svn ci -m 'Added foo baz'
  svn switch ^/trunk
  svn merge ^/branches/feature_branch .
  svn rm ^/branches/feature_branch -m 'Closed feature branch'