As far as I can see the message is not only mentioned in the element description [1] , with all the fields explained in detail, but there's even sample code to show how to parse the message in code.

What would like to be explained in addition to that?

[1] http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-spectrum.html#id389347

Oops, you're right. I didn't notice that it's explained in the Description section.

I guess I confused it with the docs for message-magnitude ("post the magnitude of the spectrum") and message-phase ("post the phase of the spectrum"). That is, "post a level message for each passed interval" made me look for a field called "level", similar to the "magnitude" and "phase" fields.

I'd suggest wording it differently, something to the effect of "if set to false, no spectrum message will be sent" or something like that. That's just my opinion though *shrug*.

I'm reopening the bug in case you agree, but otherwise this is pretty much an invalid bug.

I've rephrased the descriptions a bit, hope it's clearer now:

 2008-04-04  Tim-Philipp Müller  <tim at centricular dot net>

        * gst/spectrum/gstspectrum.c: (gst_spectrum_class_init),
          (gst_spectrum_init), (gst_spectrum_set_property),
          (gst_spectrum_get_property), (gst_spectrum_message_new):
          Rename property enums and default defines for the properties to match
          the property names and rephrase property descriptions to make them a
          bit clearer (hopefully). See #518188.