This from the Fan District Association:
Please note that there is a change in the placement of your Fan Parking Permit for Zones 1 & 2. The State Police require that the parking decal to be placed on the FRONT windshield, not on the back window as in prior years.
Acceptable placement is on the inside lower left corner (driver’s side) within one inch of the extreme left edge of the windshield with bottom of the sticker within three inches of the bottom of the windshield. Also, all old stickers must be removed. You should have received this info with your parking permit renewal application.