During investigations concerning application of LC cells as a media for dynamic holographic recording,,;, unwanted permanent recordings were observed on NLC cells with photosensitive layer (i.e., PVK-polivinylocarbazol). Applications of optically addressed NLC based cells with photosensitive layer as a re-writable media for holographic recording have been noticed. However, recent work has proved that it? these cells optical addressing can produce permanent, quasi-permanent and erasable holographic gratings, the mechanism of these phenomena was not explained. In this paper, conditions of the optical recordings in NLC cells are presented. Some basic discussion regarding physical phenomena of permanency are discussed.