does anybody know if people were forcibly tattooed in the soviet gulag system ?

Answer 1

Unlike Nazi Germany, Gulag prisoners were not tattooed by prison administration, I guess you know that.

Speaking about tattoos very popular among prisoners - they had their own symbolics and could tell other criminals, whom they are dealing (thieves, robbers etc). Some of them were "forcibly tattooed". If you read Russian, I provide a good link below (which includes some examples and descriptions). In brief - there were tattoos for unpaid card debts, rapists, police informers etc.

Answer 2

No, there was no tattooing of gulag prisoners.