How do you remove ink tag stains?

Ink tag stains are designed to be visible, so depending on the ink itself, it might not have been designed to wash out easily. Rinse the garment thoroughly, then pre-treat the stains. Repeat the pretreatment, or bleach if the fabric can handle it. Then rinse the garment and wash normally.

Addendum: I worked with ink tags in retail, and denatured alcohol (any hardware store) will remove the ink. Then launder as described above.