The practical side

The half of owning body art that nobody puts in one place. Whether you can give blood. What happens at an MRI. Whether a mole under a tattoo matters. These answers are scattered across a hundred forum threads and assembled nowhere.

Every fact here is traced to the organisation that actually sets the rule, quoted with its citation, and carries the date we last checked it. Where the answer differs between the United States, Canada and Mexico we give all of them — because a page written for one country is wrong for the others, and most pages do not say which one they mean.