From the official news piece released at the Play.Net web site:
Spring time is here and we’re bringing back our best promo deal ever. Starting today, any player who has been away from GemStone IV for more than 90 days can reactivate their account and receive a Premium (and Basic) subscription for 90 days for FREE! That’s right, you can pick up with your favorite character right where they left off.
Pass on the Code: GS2020SPRING