It does work correctly, barring `.svn` subdirectories. But, it is not as restrictive as you would like.

The preceding text already requested that people place their headers in `include/your_package_name/`. To be consistent with the other pages, that should have been `include/your_package`. But, there are cases where a different subdirectory name may be appropriate, usually for API compatibility reasons. I am trying to provide the simplest solution that works, although I do not wish to provide examples of bad practice.

Filtering the file extensions does not appeal to me. Who knows what extensions people may be using? Other variants include `.hh`, `.H`, and `.hxx`, and others that don't come to mind right now. Why drag the discussion into those unnecessary details? 

I would prefer to add a sentence after "that last command installs the entire subtree of headers", suggesting that it is a bad idea to mix other files into the header folder, but if you must, then by all means install each header explicitly by name.

The `.svn` issue *is* a problem, however. Do you recall the exact syntax for ignoring it?