With a new understanding of Russian, I found this is Half Life 2. I first started wondering why they decided to use Cyrillic to write "IED", and then I began wondering if there was an abbreviation (or even a term in the first place!) for improvised explosive devices in Russian. My dictionary did not lead me far. :( Can anybody confirm what the Russian version of the abbreviation and term IED is?
Й is not I. _Й is Y. Russian language does not have words beginning with Й. Exceptions are geogaphic names (York, Yellowstone) and йогурт (yogurt). Accordingly, the Russian abbreviation cannot have Й.– ElenaSep 3, 2021 at 13:22
The inscription is not valid: Д and Й are upside-down, but even if we assume the camera is upside-down and turn the image 180 deg, we get inverted (left-right) letter E, which is not a meaningful symbol.– AnixxSep 3, 2021 at 23:20
The Russian Wikipedia article cross-linked with the English Wikipedia "Improvised Explosive Device" article via the "Languages" list is https://ru.wikipedia.org/wiki/Самодельное_взрывное_устройство or СВУ.
The letters in your image would have to be mirror-image flipped vertically to form valid Cyrillic letters, and then you get ДЕЙ, which doesn't mean anything in particular.