ncat --chat option? How to send a string/text to a single client and not to the other clients?

ncat --chat option? How to send a string/text to a single client and not to the other clients. Hi, I've tried different separator character syntaxes to send a string/text to a single client putting : :: . : :: between the client name and the message: 0) user5:string-0 # : 1) user5::string-1 # :: 2) user5.string-2 # . 3) :string-3 # : 4) ::string-4 # :: But all other clients were receiving the string/text. **NOTE:** the (0) .. (4), just above in front of the commands is NOT part of the string/text. It's just for reference. The # is a comment and is NOT part of the string/text. It's just to clarify the character's used. Client and server real hostname is replaced by client-0.org TO client-4.org AND server. Client/server real IP's are replace by 255.255.255.251 TO 255.255.255.255. I've tried the above separator characters : :: . : :: from BOTH the client AND server, but I'm getting the same result. Of coarse I could try each and every character on the keyboard combination. Bellow is the output of 4 clients and server ********************************************* server.org : Ncat: Version 7.60 ( https://nmap.org/ncat ) Ncat: Generating a temporary 1024-bit RSA key. Use --ssl-key and --ssl-cert to use a permanent one. Ncat: SHA-1 fingerprint: XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX Ncat: Listening on :::31337 Ncat: Listening on 0.0.0.0:31337 Ncat: Connection from 255.255.255.255 on file descriptor 5. Ncat: Connection from 255.255.255.255:59186. Ncat: Connection from 255.255.255.254 on file descriptor 6. Ncat: Connection from 255.255.255.254:34210. Ncat: Connection from 255.255.255.253 on file descriptor 7. Ncat: Connection from 255.255.255.253:44194. Ncat: Connection from 255.255.255.252 on file descriptor 8. Ncat: Connection from 255.255.255.252:58691. server.org user5:client-0.org-00 user5::client-0.org-01 user5.client-0.org-02 :client-0.org-03 ::client-0.org-04 ^D ^D ^C client-0.org : Ncat: Version 6.47 ( http://nmap.org/ncat ) Ncat: Connected to 255.255.255.251:31337. 255.255.255.255 is connected as . already connected: nobody. 255.255.255.254 is connected as . already connected: 255.255.255.255 as . 255.255.255.253 is connected as . already connected: 255.255.255.255 as , 255.255.255.254 as . 255.255.255.252 is connected as . already connected: 255.255.255.255 as , 255.255.255.254 as , 255.255.255.253 as . client-0.org client-2.org client-1.org client-3.org server.org user5:client-0.org-00 user0:server.org-00 user0:server.org-00 user0:server.org-00 user0:server.org-00 user5::client-0.org-01 user5::client-0.org-01 user5.client-0.org-02 :client-0.org-03 ::client-0.org-04 user0::server.org-01 user0::server.org-01 user0::server.org-01 user0::server.org-01 user0.server.org-02 user0.server.org-02 user0.server.org-02 user0.server.org-02 :server.org-03 :server.org-03 :server.org-03 :server.org-03 ::server.org-04 ::server.org-04 ::server.org-04 ::server.org-04 is disconnected. is disconnected. is disconnected. Ncat: 131 bytes sent, 1223 bytes received in 3474.43 seconds. client-1.org : Ncat: Version 7.60 ( https://nmap.org/ncat ) Ncat: Connected to 255.255.255.251:31337. 255.255.255.253 is connected as . already connected: 255.255.255.255 as , 255.255.255.254 as . 255.255.255.252 is connected as . already connected: 255.255.255.255 as , 255.255.255.254 as , 255.255.255.253 as . client-0.org client-2.org client-1.org client-3.org server.org user5:client-0.org-00 user0:server.org-00 user0:server.org-00 user0:server.org-00 user0:server.org-00 user5::client-0.org-01 user5::client-0.org-01 user5.client-0.org-02 :client-0.org-03 ::client-0.org-04 user0::server.org-01 user0::server.org-01 user0::server.org-01 user0::server.org-01 user0.server.org-02 user0.server.org-02 user0.server.org-02 user0.server.org-02 :server.org-03 :server.org-03 :server.org-03 :server.org-03 ::server.org-04 ::server.org-04 ::server.org-04 ::server.org-04 is disconnected. Ncat: 108 bytes sent, 991 bytes received in 3445.98 seconds. client-2.org : Connection to server.org 31337 port [tcp/*] succeeded! 255.255.255.252 is connected as . already connected: 255.255.255.255 as , 255.255.255.254 as , 255.255.255.253 as . client-0.org client-2.org client-1.org client-3.org server.org user5:client-0.org-00 user0:server.org-00 user0:server.org-00 user0:server.org-00 user0:server.org-00 user5::client-0.org-01 user5::client-0.org-01 user5.client-0.org-02 :client-0.org-03 ::client-0.org-04 user0::server.org-01 user0::server.org-01 user0::server.org-01 user0::server.org-01 user0.server.org-02 user0.server.org-02 user0.server.org-02 user0.server.org-02 :server.org-03 :server.org-03 :server.org-03 :server.org-03 ::server.org-04 ::server.org-04 ::server.org-04 ::server.org-04 ^D ^D ^C client-3.org : Ncat: Version 7.70 ( https://nmap.org/ncat ) Ncat: Connected to 255.255.255.251:31337. 255.255.255.254 is connected as . already connected: 255.255.255.255 as . 255.255.255.253 is connected as . already connected: 255.255.255.255 as , 255.255.255.254 as . 255.255.255.252 is connected as . already connected: 255.255.255.255 as , 255.255.255.254 as , 255.255.255.253 as . client-0.org client-2.org client-1.org client-3.org server.org user5:client-0.org-00 user0:server.org-00 user0:server.org-00 user0:server.org-00 user0:server.org-00 user5::client-0.org-01 user5::client-0.org-01 user5.client-0.org-02 :client-0.org-03 ::client-0.org-04 user0::server.org-01 user0::server.org-01 user0::server.org-01 user0::server.org-01 user0.server.org-02 user0.server.org-02 user0.server.org-02 user0.server.org-02 :server.org-03 :server.org-03 :server.org-03 :server.org-03 ::server.org-04 ::server.org-04 ::server.org-04 ::server.org-04 is disconnected. is disconnected. Ncat: 113 bytes sent, 1126 bytes received in 3454.57 seconds.