V2 means "Volunteering 2" times a year.
Once registered as a "V2er", a resident can volunteer in events organized by any of the grassroots organizations. Every time they volunteer in an event, they will receive a chop on a card. Once they receive 2 chops on their cards within a year, they can redeem a badge and certificate at Lam Soon Community center.
After this, they are of course welcome to join in for more activities. Otherwise, they will be issued a new card in the next year to fulfill their annual V2 commitments.