When configuring an application, you can often use
/dev/null as config file if you want the application to read an empty file. But, if the application reads a list of files from a directory, you cannot use this trick. You would need to give it an empty directory to read.
I was wondering: does Linux have a default empty directory that can be used for such purposes? I know OpenSSH used /var/empty for a while, and I can of course create an empty dir myself, but maybe the FHS has specified a standard directory for this?