Syntax notation in message text

In this documentation, IP messages are described with the following syntax notation:

Non-highlighted characters: Represent the actual text of the message.
italic characters: Represent message variables. The variables are replaced by their values in the actual message.
Braces { }: Represent a group of text strings, only one of which is displayed in the actual message. The text strings are separated by or-signs (|) in the braces.
The braces and or-signs are not displayed in the actual message.
Brackets [ ]: Represent optional messages or optional parts of a message. Optional messages or optional parts of a message are displayed only under certain circumstances that are described in the "Explanation" section of the message. If an optional part has more than one possible value, or-signs separate the possibilities.
The brackets and or-signs are not displayed in the actual message.