Why can't place an ascx file in the App_Code folder?

When a developer creates a user controls (ascx files); it is not allowed to put it in the App_Code folder.

Before we answer this lets quickly remember the value of App_Code folder: it is just one of the web site project folders that can store source code BUT its content would be automatically compiled at run time. And this is reason because that would cause the user control to be compiled out of its required sequence and therefore is not allowed.

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