Choose the filename for the man page using completion, based on the
topic selected from the directories specified in `woman-manpath' and
`woman-path'. The directory expansions and topics are cached for
-speed, but a non-nil interactive argument forces the caches to be
+speed. With a prefix argument, force the caches to be
updated (e.g. to re-interpret the current directory).
Used non-interactively, arguments are optional: if given then TOPIC