Of course, the system does have restrictions. Players cannot swap in the sea, in the desert, or during Node/Conquest wars; there’s also a five-minute cooldown between swaps. The tagged character also cannot buy or sell trade items, nor can trade items be moved from inventory to storage. So you can’t just make the tagged character handle your shopping and such. But you can no doubt come up with interesting things with this mechanic; check out the full patch notes to see the other ways things have been rebalanced and improved.
Black Desert’s latest patch makes that happen. The new character tag system lets you swap out your character on the fly for another tagged character of your choice, meaning that you can hop from being a helpless low-level character struggling with a quest to a max-level dynamo for just a few moments. So now leveling multiple characters is planning for the future, not just always making new alts!
Source: Official Site