checksummed. Can be checksummed (with @file{.nock} extension removing)
with @command{nncp-check -nock}.
- Also it can contain @file{.seen} files, that should be cleaned too
- from time to time.
+ Also it can contain @file{seen/} and @file{hdr/} subdirectories,
+ that should be cleaned too from time to time.
All of that cleaning tasks can be done with @ref{nncp-rm} utility.