On duplicate key ignore?

I'm trying to finish this query; my tag field is set to UNIQUE and I simply want the database to ignore any duplicate tag. INSERT INTO table_tags (tag) VALUES ('tag_a'),('tab_b'),('tag_c') ON DUPLICATE KEY IGNORE '*the offending tag and carry on*' or even this would be acceptable INSERT INTO table_tags (tag) VALUES ('tag_a'),('tab_b'),('tag_c') ON DUPLICATE KEY UPDATE '*the offending tag and carry on*'