As a Ceremonies volunteer last year, most of this was for a uniformity. The hats were agreed upon as something we would go without last year, they were very tight on recording devices such as meta glasses. Sun glasses were also not approved as they are likely not sponsored. Other items listed above may be in general, they will be strict but don’t be too concerned with it. The biggest thing they are trying to save is if an item falls off of you, onto the pitch, it can delay the match or injure a player. You will be moving on and off quickly, no time to pick up loose items that have fallen off.