So this is becoming an issue and I want to get in front of it.
Some quick background - at the first event of the year back in October several teams were competing with both colored license plates on their robots at the same time. The alliance color they were on would face out and the opposite alliance color would face in. By lunch my referee crew and I had missed two calls because of this issue. One was a pin (we thought blue was pinning blue which is a non-issue, it turns our red was doing the pinning) and one was a mogo carry issue. In both cases glances at the robots led to us (the referees) only seeing the opposite alliance colored plate and making the wrong mental call as to which color alliance the robot was on. I should further clarify that in both cases the “back” (wrong colored) plate was clearly visible and in one case I simply could not see a correct colored plate from my viewpoint, only the incorrect color. At lunch we made an announcement that teams must have only the correct colored plate on their robots (citing R19c, and specifically the italicized portion.). With a few hiccups tournaments carried on.
Today it again became an issue. (I have opened all drivers meeting with “about license plates, only one color plates on the robot…” since that first tournament.) One team really did not like that decision. Part of their argument was that their robot design needed both plates for the plate to be held in place. My counter to that specific argument is a) I made the mistake, I’m telling you it’s not “abundantly clear” as required in R19c, and that R19a (bolded) states that plates must be nonfunctional.
But, I want to be fair and get an official ruling. Of course none of this is helped by the fact that plate color meant so little last year.
It is up to the head referee’s discretion whether the alliance color is “abundantly clear” or not; your experience with confused rulings is exactly why this rule is in place.
This would definitely be a case where a team would need to revisit their plate placement or robot design to improve their compliance with rule R19c.
Teams who “stack” both colors of license plates should expect additional scrutiny from referees and inspectors as to whether or not the correct color is abundantly clear. To help avoid confusion, teams who use this design approach are advised to position their plates with VEX metal or another non-functional decoration behind them to hide the incorrect color.
For example, the robot in the image below <R19> in the Game Manual could have blue plates stacked and “hidden” behind the visible red one, and it would not cause any confusion.
