[aciurczak]

I think you may be missing the point. The file that needs to be written to may need pretty open permissions to work. Yet the search engines assume that this file will be in the forum root. This hack includes instructions on how to deal with both of these. It puts the file within the vbseo folders, you can open up permissions on that subfolder without opening up permissions on your higher level forums directory. Then the htaccess rule points browsers and search engines looking for that specific file in the forums directory, and feeds them the file (transparently) from the subdirectory. Yes, you probably can get this hack to work by writing the file directly to the forums directory, but you don't want to; you just don't know that yet.