For @directives, I am understanding from MSDN docs that you are not supposed to use them in include files.
MSDN docs with initial claim.
The docs offer little in the way of a "why" and further searching on the docs, these forums, and google has turned up nothing.
My issue is that I would think if you (or myself in this case) had an application where you knew that your directives would be the same for all pages for the life of the application, you would probably just want to place all the directives in one file and include that file at the very top of your page.
Hope this isn't obvious...