web.config inheritance with Asp.Net
Imagine you have a website, but when people connect via a webservice to the application you want to change the configuration of how they interact e.g maximum upload size. Well with Asp.Net I found out that you can.
Providing the Machine.config located at
systemroot\Microsoft .NET\Framework\versionNumber\CONFIG\Machine.config
says that a node can be modified.
e.g. node in the machine config does not have the setting
allowDefintion="MachineOnly"
But instead looks like this
<section name="sqlCacheDependency" type="System.Web.Configuration.SqlCacheDependencySection, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" allowDefinition="MachineToApplication"/>
Then inheritance applies to that node.
The important point is that with inheritance the child configuration settings take priority.
You can even do a underneath a node as noted in this Stack Overflow discussion
Read this msdn article for a detailed description of Asp.Net configuration file heirarchy and inheritance.