It annoys me when I see people write on or dog-ear the pages of library books. Even with my own books, I never write on them or bend pages. I use bookmarks and if I want to note pages for future reference, I use small sticky tabs that peel off easily..
Here is another peeve where I agree with Rat.
Even if I am not straddling the line on either side, if I am too close to one line, I back out and re-park so that I am almost in the middle of the two lines. Not only is it a courtesy to those parking next to me, it also reduces the risk of the other driver accidentally hitting my car.