nodelete Switch

The nodelete switch can be used to prevent overwriting existing files if they already exist on the destination system. For example:
 
transmit/nod *.*

would transfer all the files in your current account that don't already exist on the remote system.

The nodelete switch can be used with these file transfer commands:
 

transmit and receive    ztransmit and zreceive

The nodelete switch is very similar to the noerase option.

Note With ZMODEM file transfers, nodelete may not be used with the hash, different, longernewer, newer, or append switches.