Grading Barber Quarters Hub #2

@KBBPLL . I know this is your specialty but I have a specialty question. I was reading the book you gave me last night and came across an extrodinary quote. I will parapharase from Pg. 179 of "The Guide Book on Barber Coins": The book has a quote from David Lawrence saying that all Barber Quarters struck from 1901 on must be graded using a different standard. It goes on to claim the "bands" under the word "Liberty" might be missing and that the entire head design will be much flatter than on earlier coins.
I am in the middle of preparing to buy my first Barber Quarters. I can't find any other mention of this in my usual grading guides. Is there a specific grading standard and if so where do I find it? Anyone who knows about tis; please feel free to enlighten me. James