-algorithms. Data is splitted on 128 KiB blocks. Each block is encrypted
-with increasing nonce counter.
+algorithms. Data is divided on 128 KiB blocks. Each block is encrypted
+with increasing nonce counter. File is deletes immediately after
+creation, so even if program crashes -- disk space will be reclaimed, no
+need in cleaning it up later.
+
+If @file{SRC} points to directory, then
+@url{https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_01, pax archive}
+will be created on the fly with directory contents and destination
+filename @file{.tar} appended. It @strong{won't} contain any entities
+metainformation, but modification time with the names. UID/GID are set
+to zero. Directories have 777 permissions, files have 666, for being
+friendly with @command{umask}. Also each entity will have comment like
+@verb{|Autogenerated by NNCP version X.Y.Z built with goXXX|}.