The whole thing about tattoos started under Clinton. At one time he ordered that the Army (other services too, I’m sure) examine all serving members for “racist” tattoos. Those with such tattoos were then either required to have something tattooed over them, or be discharged. I worked for the Veterans Administration, and saw several vets who had Celtic crosses on their lower legs who had been discharged for that very reason.
However, gang tattoos and racial tattoos on minorities were not to be observed or punished.
A former co-worker described how her brother was only allowed to enlist when a tattoo of an eagle on a swastika was altered so it became an eagle on a cannonball - and this was 20+ years ago.