Can Liquibase move tags?

What happens if I tag a database, then update it with new change sets, and then tag it once more with THE SAME tag? Will the tag move from pre-updates to post-updates, or will Liquibase reject that?

Is that behavior GUARANTEED or could it change at any time?

Liquibase will add the tag and there will be duplicate tags in the tag column. It is not set up as a unique column.