It is also a way to celebrate the 14th conference on trans health that will take place in the city from June, 4 to June, 6 at the Pennsylvania Convention Center. The conference is free. You can find more information about it here: http://www.trans-health.org/.
Philadelphia has already got used to fly the rainbow flag every month of October to celebrate the Coming Out Day, perhaps it will do the same for the trans* flag.
Photo by torbakhopper/Flickr