Messages

Messages are the game's text, such as dialogue, signs, and item descriptions. They're in .msg files in msg/, such as msg/0C_Chapter1.msg:

#message:0C:(CH1_0001) {
	[Style right]
	[Wave]Oh, no! Stupid Fuzzy![BR]
	Get back here with my shell![Wait][End]
}

Each message starts with #message:, its section, and its name in parentheses. Its constant is MSG_ and its name, such as MSG_CH1_0001, which your code shows it with. No two messages can share a name.

To find the code that shows a message, Ctrl+click its name (Cmd+click on macOS).

Adding a message

Add a new message to a .msg file, with a name no other message uses. To start a new file, right-click msg in the Filesystem and select New > Message Section. Diorama64 gives the new file a section number one higher than the highest section any message uses.

Tags

The text in square brackets is tags, which control how the message prints:

Tag	What it does
[BR]	Ends the line. The game doesn't wrap lines, so end each one with [BR].
[Wait]	Waits for the player to press A.
[Next]	Moves on to a new page of the box.
[Pause 10]	Pauses for 10 frames.
[End]	Ends the message, and closes the box.
[Style right]	Sets the box's style, such as a speech bubble.

For every tag, see Message markup.