Here's my blocking notation for Proof. I am accepting questions. I noted this on the sheet but I will say that the specific organizational symbols I used for my blocking are really only applicable to two person scenes, I'm aware. I would probably switch it up and go harder on the color coding for scenes with more people in them (esp since the color coding wasn't super visible in this scan, unfortunately).
Ooh, I love the system of each "landing place" being notated a little differently so it's easier to reference when the character is there! You could also just add the character's initial to your alphanumeric system if there were more than two characters (so you'd end up with C1, C2, etc.) if that was more convenient for you than doing more color coding.