Flogging Molly question

Wed Feb 22 7pm Doors. Due to the promotional nature of this event, this show is 21+.

What about the event makes it such that it's 21+? Will there be free or reduced price Guinness for all? Will beer be sold at the all ages show on the 21st?
The only difference that either of these shows will have from our normal operating procedures is the 21+ nature of the 21+ show. It is a tour policy regarding the show that will have Guinness sponsorship ( no beer discounts, just posters and coasters and such).