Hello Dan Brown,
In your new tutorials, you chose to use 2U to represent a double turn of the U-layer. The overwhelmingly standard notation for this is U2, and 2U, if anything, has a different meaning. Every Rubik's cube expert in the world, every world record holder, even every intermediate cuber, would tell you this, and if you really want, I can have them tell you.
I don't think you realize this, but by telling this to a lot of beginners (your videos, if not accurate in notation, are still appealing to new people with a cube), you are making things very difficult for us. It's like teaching children the wrong order of operations for arithmetic.
I appreciate your decision to move to the prime notation for counterclockwise, although I'd like to note that the prime is really just a normal apostrophe: F', not F′.
Is there any good reason for your choice of 2U, and is there any chance we could implore you to correct this?
»Lucas Garron