====== FHS ======

  * http://refspecs.linuxfoundation.org/fhs.shtml
  * http://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch05.html : « Applications must generally not add directories to the top level of /var. Such directories should only be added if they have some system-wide implication, and in consultation with the FHS mailing list. »