Commands in HexChat are prefixed with / and to escape them you can type it twice e.g. //
HexChat will first try to run plugin commands, then user commands, then client commands, and lastly send it directly to the server.
User commands can be used to create aliases, to run multiple commands at a time, or more complex custom commands. They are set in.
An alias is just a shortcut refering to an existing command, for example /j refers to /join &2
Naming two user commands the same thing will run both in the order they are listed.
For more complex commands you can use these codes:
To get a full list of commands and what they do type /help -l.