A suggested enhancement is to allow sender-side protection rule filters to prevent/allow deletion of files. Currently there are receiver side protection rules but none for senders.
Suppose a user wants transfer file A and file B using rsync. After the transfer file B on the sender side is desired to be deleted by using the --remove-source-files option. However currently there doesn't seem to be a way to protect file A from being deleted if both file A and B are included in the same rsync call.
The user could separate the single rsync call into two rsync calls, one with and one without the --remove-source-files option.
If this sender-side functionality already exists then please disregard.