14.15.5 @error{} (error-->): Indicating an Error Message

A piece of code may cause an error when you evaluate it. You can designate the error message with the @error{} command.

The @error{} command is displayed as ‘error-->’ in Info and HTML and as the word `error' in a box in the printed output.

Thus,

@lisp
(+ 23 'x)
@error{} Wrong type argument: integer-or-marker-p, x
@end lisp

produces

(+ 23 'x)
error--> Wrong type argument: integer-or-marker-p, x

This indicates that the following error message is printed when you evaluate the expression:

Wrong type argument: integer-or-marker-p, x

‘error-->’ itself is not part of the error message.