Thank you for this reply!

Sorry to burst your bubble but it'll cost 19.99$.

http://blog.raft-game.com/2018/04/06/blog-32-a-date-has-been-set/

"We can also announce that Raft will be sold for 19,99 USD. "

Those tags are USER DEFINED and developer has nothing to do with them.

It's free prototype and haven't been updated for over a year.