(Clearwisdom.net)
After the Clearwisdom editors sent out an announcement regarding Teacher's 
instructions to change some words in Zhuan Falun, some practitioners have 
been concerned about marking up the book and how this can be done. My 
understanding is that this question was answered by Teacher in "Teaching the Fa 
at the Meeting with Asia-Pacific Students",
"Question: Recently you mentioned that certain words in your writings 
    need to be revised. Can we directly paste the correct words over the old 
    ones, instead of scratching the old ones off?
    
    Teacher: Actually it's fine however you do it, as long as you correct 
    them. The students in Mainland China don't have the means to do this. I know 
    that in the past, most of the books printed in Mainland China used 
    newsprint, and it was pretty thick, so it won't be damaged if you scratch it 
    lightly with a thin blade. I'm just giving you an idea. You don't have to do 
    it that way. (Audience laughs)"