Engraving ones ID on stereo gear was somewhat common back in the day. I case of theft the markings might help police in returning stolen items back to their rightful owner.
Even though I feel big large heavy stereo gear is not a prime target as it used to be, I still engrave some sort of ID on any gear I acquire. I usually hide it, often inside the cabinet.
I was never one who scrawled writing or numbers on the faceplates of gear. In my mind that was tacky and probably devalued the gear.

I had about 200 albums stolen my last year in college. I always wrote my name on them. Sure didn’t stop the thief. A few years later I came across one of the albums in a pawnshop about 180 miles away.
Names on records were to keep people honest at parties.
The Electric Prunes
I see a lot of older albums signed by the owners.
Then there is the drivers ID inscribed on face plates of gear.
Any stories how or why could be interesting
What ya got?