| 摘要 |
<p>Window envelope (1, 40, 50) arranged to reveal opposite a first portion of window, after marking a first internal zone (11, 43, 56) of the envelope, a second previously hidden internal zone (16, 44, 70), comprising a mobile sheet (17, 46, 56) inside the envelope comprising the said first zone, arranged to move opposite the window in an irreversible manner between a first position and a second position, a transparent sheet (21, 41, 61) for protecting the mobile sheet opposite the window and means of irreversible displacement (20 ' 60) in a predetermined direction, by an operator, of the mobile sheet between these two positions. <IMAGE></p> |
