The wise wordsmith who helped create the ad at left might want to attend NMC's "Courting The Muse" writer's conference.
Luring somewhere in the session descriptions may be a workshop that explores the difference between "playwriting" and "playwrighting".
While it's true that a "playwright" writes a play, the craft's correct term is "playwriting". If you don't believe Miss Fortune, the Yale School of Drama’s Playwriting department might convince you.
Miss Fortune is always available as a proofreader--just sayin' as I file this one under "irony".