How is the order of execution for HttpModules determined?

According to this forum post, HttpModules are executed in the order in which they were registered. This makes sense to me, because otherwise the <clear> and <remove> directives would also not work as expected, e.g. when used like this:

<httpModules> 
   <clear/>
   <add... />
</httpModules>

According to the Internet Information Services (IIS) 7.0 Resource Kit book extract from Microsoft Press,

To resolve such relative ordering dependencies, the administrator can control the relative ordering of modules by changing the order in which they are listed in the modules section.

This works because the server uses the order in the modules configuration section to order module execution within each request processing stage. By placing module A before module B in the list, you can allow module A to execute before module B.