To thwart fear, uncertainty, and doubt, the man page should disclose default values.

In particular, as a huge amount of data was being downloaded it was
unclear where the files were being dumped. They were not being dumped
in the user-specified target directory. The operation was interrupted
yet what was fetched so far was not in the target dir. Yet several
gigs of hard drive space was consumed. Apparently this was because of
somewhat undocumented caching.