pg_restore --multi-thread

I know we've already had a discussion on the naming of the pg_restore -m 
option, but in any case this description in pg_restore --help is confusing:

-m, --multi-thread=NUM   use this many parallel connections to restore

Either it is using that many threads in the client, or it is using that many 
connections to the server.  I assume the implementation does approximately 
both, but we should be clear about what we promise to the user.  Either: 
Reserve this many connections on the server.  Or: Reserve this many threads 
in the kernel of the client.  The documentation in the reference/man page is 
equally confused.

Also, the term "multi" is redundant, because whether it is multi or single is 
obviously determined by the value of NUM.