+dit(bf(-k, --skip-empty-dirs)) This option tells the receiving rsync to get
+rid of empty directories from the file-list, including nested directories
+that have no non-directory children. This is useful for avoiding the
+creation of a bunch of useless directories when the sending rsync is
+recursively scanning a hierarchy of files using include/exclude/filter
+directives. This also affects what directories get deleted when a delete
+option was specified (but keep in mind that excluded files are also
+protected from deletion).
+
+Here's an example that copies all .pdf files in a hierarchy, only creating
+the necessary destination directories to hold the .pdf files, and ensures
+that any superfluous files and directories in the destination are removed
+(due to a hide filter on non-directories being used instead of an exclude):
+
+quote( rsync -avk --del --include='*.pdf' -f 'hide! */' src/ dest)
+