Since one of the popular components of AJAX file upload uses a namespace qqand parameter qqfile. The filenamespace prefix should probably avoid collisions with other parameters in the form. I don’t know why the author preferred qqas a namespace for his component, although it is neither like downloading a file nor its website valums.com. He might want something short, like $, which does not conflict with existing popular libraries.
https://github.com/valums/file-uploader