title: How does preCondition="managedHandler" work for modules?
body: <p>After reading some documentation about the integrated pipeline I'm confused about how IIS determines when to run managed modules, what a managed request actually is, and how that is determined, e.g.:</p>
  
  <p><a href="http://www.iis.net/learn/application-frameworks/building-and-running-aspnet-applications/aspnet-integration-with-iis">http://www.iis.net/learn/application-frameworks/building-and-running-aspnet-applications/aspnet-integration-with-iis</a>
  <a href="http://blogs.msdn.com/b/tmarq/archive/2007/08/30/iis-7-0-asp-net-pipelines-modules-handlers-and-preconditions.aspx">http://blogs.msdn.com/b/tmarq/archive/2007/08/30/iis-7-0-asp-net-pipelines-modules-handlers-and-preconditions.aspx</a></p>
  
  <p>"Managed" requests are mentioned several times. There's one instance where it is explained that a managed request is a request that has a mapping to a managed handler. There's also a quote saying that a handler is a "special" module (second link).</p>
  
  <p>Modules are described as something that runs for <em>every</em> request and that a handler has a mapping that specifies when it should run (e.g. HTTP GET for *.aspx) (second and first links). Furthermore, for the modules the execute_request_handler [which I'm assuming as the point where the handler actually runs] comes after several stages of the pipeline (after begin_request, authenticate, authorize, etc...), it implies that there's a step that happens before all that, that establishes that the request is for a managed handler, so as to disable the execution of modules that have the preCondition="managedHanlder" when the request is not for a managed handler.</p>
  
  <p>I feel there's something I'm missing here, can someone shed some light about how does preCondition="managedHandler" exactly works?</p>