Today the official criteria for this year’so Signature Events was released. There are a lot more requirements than there were last year, including a lot about the qipuality of the experience at the event.
Signature Events are supposed to have at least one Certified Referee for each division, experienced volunteers for several other positions (the Judge Advisor and some of the inspectors) and a certain minimum number of volunteers for certain other things. (At least two Referee/Scorekeepers per division who have watched/read all of the refereeing materials, at least two judges for every 10 teams, and at least one inspector for every 8 teams.)
Also, in order for the Tournament Champions from the event to qualify for Worlds, the event needs to be at least two days long, with at least 3 matches each day, and it needs to have at least 40 teams (post live results to VEX Via). If it doesn’t do these things, it can still qualify the Excellence Award winner to Worlds if it has at least 24 teams (and does certain other things).
Edited to add:
They also recommend (or require) that Signature Events give banners and customized trophies to the winners, and have raised fields (10-24 inches), opening (and closing) ceremonies, and at least two announcers.
And in this year’s Qualifying Criteria, the rules say that if a team qualifies for Worlds from a Signature Event and then at States, the spots from States will go to the team with the next best Skills score in the state - they did this last year, too, but it wasn’t mentioned in the Qualifying Criteria.
Likewise, if a team qualifies for Worlds at States and then at a Signature Event, their spot will go to the next best Skills score at the Signature Event (among teams who haven’t qualified for Worlds).
As @dhmmjoph pointed out, it’s actually a minimum of 2 Scorekeeper/Referees (basically assistant referees) per field set (set of fields that rotate between tches which is usually one per division), not two per field as I initially wrote.
Come to think of it, that makes the most sense, since the three referees would only be needed at one field at a time (unless they had it where 1-2 people scored one field while other referees were watching a match on another field).