Oh. It is mandatory for EVERYONE this year. So if there is more than 1 team they will have it because they are awarding trophies to everyone in the top 10. So you are competing to be the best in the US on Friday. You could win that. Then Saturday you are entering Prelims/Semi-Finals for Worlds. You may come in 5th and not move on to compete in the finals even though you were the top team in the US on friday.
NEW: Following the completion of the U.S. Worlds Trials divisions the USASF will award trophies to the top 4th – 10th place teams, US Worlds Trials Gold, Silver and Bronze trophies and medallions to the top 3 teams.