Any of the file names specified may be prefixed with a system name, meaning that the file should be transferred to or from the remote machine specified. The system name is separated from the file name by either a '!' or a ':' character.
Only one remote system may be specified for each rcp command, and all the source files must live on the same system. It is not possible to move files from one place to another on a remote machine - they must transfer across the ethernet connection. This is a restriction imposed by the protocol.
rcp oscar!/usr/dave/file.c /usr/tmp
Copies the file /usr/dave/file.c from the system oscar to the destination /usr/tmp on the local system.
rcp /usr/dave/src/rcp.c myprog olive:/usr/dave/public
Copies the local files /usr/dave/src/rcp.c and myprog, to the destination /usr/dave/public on the system olive.
In the event of a protocol failure, the remote server may terminate rcp. There should be a diagnostic message - consult your guru.
rcp a:file1 b:file2 c:dest
are NOT allowed.
You can't move things around on the remote host - you can only copy from one host to another.
The file transfer protocol is a home-grown variety, and is not going to be any sort of standard. It would be nice if it used TCP/IP, or some other well-defined protocol.