Hudson 1.20 and earlier used to create redundant directories inside the workspace. For example, if the CVS module name is "foo/bar", it first created "foo/bar" and then put everything below. With this option checked off, there will be no more such unnecessary intermediate directories.

This affects other path specifiers, such as artifact archivers --- you now specify "build/foo.jar" instead of "foo/build/foo.jar".