Powerful svn merge

Since I'm always using svnmerge.py to do the merge stuff, I have no chance to go through the svn merge doc.
Now I just found svn merge is so powerful.

If you just want to merge one pic of change from trunk to branch, you don't have to do the

svnmerge.py init

svnmerge.py merge ...

You can just type in you working copy directory

svn merge -c VERSION YOUR_TRUNK_URL [WCPATH]

If you want to revert the change for the svn server side , not just your working copy

svn merge -rVERSION:VERSION-1 SOURCE [WCPATH]