Fasten Envelope, Registered cover, King George VI, 1949, EXPERIMENTAL B. O., Block of Four of 1 ½ Annas & pair of  ½ Anna affixed on the back side of the cover, dispatched to “DEVOKOTTAI, Ramnad Dist. fasten envelope slip attached, with the instruction of Re-USE this envelope in Roman, Devnagari & Persian script and “O. H. M. S.” printed on it, Registered Label affixed as “R 123 | EXPERIMENTAL B.O. | MS – 194”, on the reverse of the slip the instruction for pasting this slip is mentioned in Roman, Devnagari & Persian script. Dispatch seal “EXPERIMENTAL B. O. | 21 JLY 49” applied twice, another dispatch seal of “?? | REG | 21 JLY 49”. Round delivery postmark “DEVKOTTAI | REG | 22 JLY 49 | 2 45 P.M.” on the reverse of the cover, very good condition, Very Rare.

Note: An important cover that was probably made by an eco-friendly enthusiast, as per the Government advisory. In the reign of George VI, it is possible that the term Fasten Envelope was not commonly used or may have been used to refer to a particular practice or service that is not well documented as a whole. According to postal terminology, "FASTEN ENVELOPE" refers to a process of ensuring an envelope's contents are protected and remain intact during transit through adhesive or other means.