My stupid saddle question o'the day :)
I feel stupid asking this, but I would like to know and the only way to learn is to ask. So...
This is one of my saddle rails. What are the markings for and what do they mean? Do I need to stay within those markings for the saddle to be safe to use? Like I said, dumb newbie question

Thanks.
"A bicycle does get you there and more. And there is always the thin edge of danger to keep you alert and comfortably apprehensive. Dogs become dogs again and snap at your raincoat; potholes become personal. And getting there is all the fun."