--- /dev/null
+include(header.m4)
+include(loglevel.m4)
+<qu>
+option "filter" f
+#~~~~~~~~~~~~~~~~
+"Specify filter."
+string typestr="filter_spec"
+optional
+multiple
+details="
+ May be given multiple times to 'pipe' the stream through
+ arbitrary many filters in an efficient way. The same filter
+ may appear more than once, order matters.
+
+ Filter options may be specified for each '-f' option
+ separately. Note that you will have to quote these options
+ like this:
+
+ -f 'compress --inertia 5 --damp 2'
+"
+</qu>