What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Narrative: the flight crew of both aircraft involved were unclear of the meaning of the markings used in the "penalty box" holding bay charts and manuals supplied to the crews by united air lines did not adequately reflect the changes in the most recent advisory circular that the markings were based on. There are presently no restrictions on the type of aircraft that can use the holding bay under normal operations. Large aircraft would have a very difficult time using the holding bay and remaining behind the hold line.
As the FAA filed it
NARRATIVE: THE FLIGHT CREW OF BOTH AIRCRAFT INVOLVED WERE UNCLEAR OF THE MEANING OF THE MARKINGS USED IN THE "PENALTY BOX" HOLDING BAY CHARTS AND MANUALS SUPPLIED TO THE CREWS BY UNITED AIR LINES DID NOT ADEQUATELY REFLECT THE CHANGES IN THE MOST RECENT ADVISORY CIRCULAR THAT THE MARKINGS WERE BASED ON. THERE ARE PRESENTLY NO RESTRICTIONS ON THE TYPE OF AIRCRAFT THAT CAN USE THE HOLDING BAY UNDER NORMAL OPERATIONS. LARGE AIRCRAFT WOULD HAVE A VERY DIFFICULT TIME USING THE HOLDING BAY AND REMAINING BEHIND THE HOLD LINE.