message is logged in the log file.
Similarly, if the property name is mis-spelt no error message is
-produced, and clearly the expected action cannot be performed. If
+produced, and clearly the expected action cannot be performed. In
fact, you can set any (fictitious) @q{property} using any name you
like in any context that exists by using the @code{\set} command. But
if the name is not known to LilyPond it will not cause any action to