The Reference Manual shows an embedded url in its example for the client-side-only retrieveMessageText attribute.

The Reference Manual correctly says "This attribute is meaningful only if used with the network driver." Then the retrieveMessageText section goes on to show an example using an embedded url: "jdbc:derby:salesDB;retrieveMessageText=false". Instead, the example should show a network url, just like the examples for the other attributes which only make sense for network urls: traceDirectory, traceFile, traceFileAppend, traceLevel.