OSRAM 100W GLS incandescent bulb "Property of HM Government" lit up

From the huge box from that FB seller this evening

The etch was very very faint but luckily I managed to read it when I held it against the 36W fluorescent fixture in my office room

Larger than usual 100W incandescent GLS bulb but with a short neck (usually the neck be slightly longer)

Says "Property of HM Government" on the etch