Hrvoje> Adrian Aichner <aichner(a)ecf.teradyne.com&gt; writes: Hrvoje> Use warn_when_safe() as you would use the Lisp function Hrvoje> `display-warning', except that warn_when_safe() accepts format Hrvoje> parameters a la `message'. Ah, that gets me started. Thanks! Hrvoje> Huh? `grep warn_when_safe *.c' will give you tens of Hrvoje> examples of usage. This is true. I still find it hard though to deduce correct usage from examples. I used stderr_out because I found examples of its usage in the first place :-) Are there any rules how to pick the correct level amongst these: The recognized warning levels, in decreasing order of priority, are 'emergency, 'alert, 'critical, 'error, 'warning, 'notice, 'info, and 'debug. Thanks, Adrian