There is provided a thermal transfer sheet that includes a heat-resistant slipping layer and a colorant layer, the heat-resistant slipping layer and the colorant layer being formable in an in-line process, has excellent heat resistance, and can suppress tailing. A gas generant having nitroguanidine and phase stabilized ammonium nitrate has many desirable characteristics such as little production of ash and the production of essentially toxic free exhaust gas. A method of manufacturing a magnetic recording medium, according to one preferred embodiment, includes providing a nonmagnetic substrate; arranging an anti-ferromagnetic layer on the nonmagnetic substrate; forming a plurality of carbon nanotubes extending perpendicularly from the anti-ferromagnetic layer; and forming a plurality of magnetic nano-particles contained in the carbon nanotubes. Before the reading is complete, an updated entry of the domain name blacklist is received, a new record to the domain name blacklist is added, and the entry being read is placed into a garbage pool having a current version number.