[Qgis-user] QML reference, symbolize synonyms alike

[Schweitzer, Peter]

Is there a QML reference document?

What I really want to do is specify that two different category values
will have the same symbol, like this:
<category render="true" symbol="64" value="carbonate rock"
label="Carbonate rock"/>
<category render="true" symbol="64" value="carbonate" label="Carbonate rock"/>
I want to read this as

when the value of the attribute is EITHER "carbonate rock" OR
"carbonate", render the feature using the symbol named "64"

But this does not have the effect that I want, so I'm thinking
incorrectly about how the QML file works.

I would welcome advice on how to do what I want, or direction to the
QML reference, or both.

Thanks!

Peter
-- 
Peter N. Schweitzer (U.S. Geological Survey, Reston, VA 20192)
(703) 648-6533  email: pschweitzer at usgs.gov
http://geology.usgs.gov/peter/