This article is from the Theatre FAQ, by aku@leland.Stanford.EDU (Andrew Chia-Tso Ku) with numerous contributions by others.
Broadway producers assign a few seats to every performance to The
Actor's Fund of America to help raise money for the Fund's charitable
work in the entertainment industry. Seats are double the box office
cost (1/2 is a charitable donation). Tickets are on a first-come,
first-served basis (subject to availability) (212) 221-7301 ext 133.