+diff. If you use git-svn, a git diff or patch is OK
+too; likewise a quilt patch, if you use quilt.
+
+It should be a "good patch": focus it on a single
+issue, and make it be easily reviewable. Don't make
+it so large that it's hard to review; split large
+patches into smaller ones. (That can also help
+track down bugs later on.) All patches should
+be "clean", which includes preserving the existing
+coding style and updating documentation as needed.j