This idea is not for the reel but for the line. I figure the reel could be used for several weight lines and I would mark the line so that you will always know what the line is and that way it would make no difference what reel it is on. I mark the end of my fly lines, about 6 inches from the end, with a magic marker. I use dashes or a small magic marker ring around the line. Four rings equals a 4 weight, 5 rings for 5 weight, etc. Some use a wide ring to represent a 5 weight and smaller rings for anything over a 5. In other words, a wide ring is for 5 and 2 smaller rings would be 5 plus 2 or 7 weight.

Just a thought and what I do. I do this because sometimes I switch a particular line weight from one reel to another to see if a heavier reel feels or balances the rod I am using better. I always know what weight the line is no matter what reel it is on.