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This is nc from the netcat-openbsd package. An alternative nc is available
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in the netcat-traditional package.
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usage: nc [-46bCDdhjklnrStUuvZz] [-I length] [-i interval] [-O length]
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  [-P proxy_username] [-p source_port] [-q seconds] [-s source]
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  [-T toskeyword] [-V rtable] [-w timeout] [-X proxy_protocol]
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  [-x proxy_address[:port]] [destination] [port]
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  Command Summary:
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       -4        Use IPv4
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       -6        Use IPv6
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       -b        Allow broadcast
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       -C        Send CRLF as line-ending
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       -D        Enable the debug socket option
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       -d        Detach from stdin
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       -h        This help text
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       -I length    TCP receive buffer length
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       -i secs     Delay interval for lines sent, ports scanned
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       -j        Use jumbo frame
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       -k        Keep inbound sockets open for multiple connects
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       -l        Listen mode, for inbound connects
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       -n        Suppress name/port resolutions
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       -O length    TCP send buffer length
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       -P proxyuser   Username for proxy authentication
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       -p port     Specify local port for remote connects
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       -q secs     quit after EOF on stdin and delay of secs
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       -r        Randomize remote ports
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       -S        Enable the TCP MD5 signature option
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       -s addr     Local source address
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       -T toskeyword  Set IP Type of Service
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       -t        Answer TELNET negotiation
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       -U        Use UNIX domain socket
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       -u        UDP mode
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       -V rtable    Specify alternate routing table
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       -v        Verbose
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       -w secs     Timeout for connects and final net reads
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       -X proto     Proxy protocol: "4", "5" (SOCKS) or "connect"
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       -x addr[:port]  Specify proxy address and port
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       -Z        DCCP mode
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       -z        Zero-I/O mode [used for scanning]
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   Port numbers can be individual or ranges: lo-hi [inclusive]