As outlined by San Francisco news site Hoodline, the auditorium is booked for a private event through September 13, with SFPD officers and private security guards patrolling the perimeter of the building.
Documents filed with the San Francisco Planning Department say the event is a "trade show" set to run from September 4 until September 10, which lines up with the timeline when Apple is expected to hold its event, but there are some potential red flags that make it unclear whether Apple is the company booking the event space at the auditorium.
In investigating the documents filed with the Planning Department, MacRumors learned the space is being used by a company known as "Adams and Associates," which has no known ties to Apple. Additionally, there are very detailed documents that describe the removal of four window panels to accommodate an "exterior wall mounted star graphic sign." The star is depicted in two different ways in separate documents -- both as a standard star shape and as an oddly-shaped star with points at unusual angles.
As Hoodline suggests, it's possible the star-shaped logo is a placeholder for an Apple logo, but a structural document supplied by an engineer on the project includes detailed, specific calculations and drawings for the star shape that cast doubt on the theory that it could be a placeholder logo.
In past years, Apple has held its iPhone-centric September event at several different locations around the Bay Area, so it would not be unusual for the company to choose a previously unused event spot. Its 2014 event was at the Flint Center in Cupertino, while its 2011 and 2013 events were held at its own campus. In 2010 and 2012, the events were held at the Yerba Buena Center For the Arts.
It's not yet known if Apple is preparing the Bill Graham Civic Auditorium for its September 9 event, but with only 16 days to go until that date rolls around, we should be getting confirmation on Apple's plans in the form of media invites in the very near future.