This command will define settings for the specified room. Since the server bot works in conjunction with the chan commands, your server bot will keep your room's topic and modes if you configure the server bot to do so.
ADMINPASS - Set a Zone password.
BOT - Define which bot to use.
JOINFURL - Force a URL on a local Java user.
MODE - Set the default room modes.
OPFURL - Allow channel operators to furl to channel users.
PASSWORD - Set the room's password.
QUEUE - Channel queue configuration.
TOPIC - Set the default topic.
/as help chan set <command>
The bot will set the topic or mode each time the server restarts. If the modes conflict with a modelock set for the room, the bot will override the modelock. You can also use the bot to set a specific key or limit, which you cannot do with a modelock. Normally you should not set a mode that conflicts with the modelock, but you might wish to do it with l or k. This would allow you to have a set key that should be kept set, yet if anyone tries to change the key, services will not let them to set a new key. This means that the room will always either have the key that you set or it will not have a key. But it will not be keyed to prevent people who should be able to join from joining. You will generally want to use a topiclock if you want a specific topic.