Where is the project-config.xml element for "Do not run new build if there is a suitable one"

I'm working out how dependency builds are added to the queue by the Snapshot Dependency mechanism.  I've found it easier to find what I need to know by grepping through the project-config.xml files.  One thing that seems very important, that I haven't found evidence of in the XML is the state of the "Do not run new build if there is a suitable one" snapshot dependency option.  I think it's because I don't know how to interpret the configuration, but I can't be sure.  When the option is enabled in a "depends-on" element, I only see the following.  One of these might imply "Do not run new build if there is a suitable one" is true, but I can't tell how that should work:

<depend-on sourceBuildTypeId="bt7">
          <options>
            <option name="run-build-if-dependency-failed" value="true" />
            <option name="take-started-build-with-same-revisions" value="true" />
            <option name="take-successful-builds-only" value="true" />
          </options>
        </depend-on>

So, how do I find whether it's true or false?