A rod loop on a fishing shirt is is usually found above the pocket on the left side of the shirt. The loop may be sewn in permanently or can be opened on one side by a piece of velcro. It is primarily designed to hold a fishing rod, but can be used for other purposes.
Slide the tip of the rod through the rod holder loop until the butt or end of the rod can rest on the ground on its own. You now have both hands free to change a leader, or add a tippet which is the end section of line to which a fly or lure is attached.
The loop is a convenient place to hang your glasses for easy removal. Use the rod holder to hold a pair of glasses by slipping one temple through the loop. The temple is the hinged stem connected to the side of the rim.
Forceps are an important piece of fishing equipment. They are used to remove hooks from a fish's mouth and can be conveniently attached to the rod holder by pinching the ends of the forceps on the loop.
You can use the rod holder to attach a nail clipper or line clipper to the rod holder loop with a retractable spool.
Leader or Tippet Spool Holder
You can use the rod loop to hang a spool of leader or tippet material to the loop with a retractable spool.