Post
You have identical fishing outfits. You notice while fishing that there is a fray in the line. How do you know which outfit needs your attention when you get back to the dock?
A numbering system is the answer. You can use an engraving tool to inscribe a small number in some inconspicuous but visible place. I prefer to use a label maker and stick a number on the side plate of the reel on all my fishing outfits that look exactly alike. When I notice something that needs my attention I make a mental note of the number for later identification.