Drupal: can I manually place files in my "files" folder?

I'm adding some pictures to my Drupal files folder.

I was wondering if Drupal remove the files not connected to any no开发者_开发知识库de as scheduling routine, from the files folder.

In other terms, I was wondering if I can place files into the "files" folder or if these can be deleted by the system

thanks

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If you place a file with fx FTP Drupal wont delete them, it will only delete files it know about that are labeled temporary in the file system, like images generated by the ImageCache module, or js/css compressions.