These small markers are designed to hold a nylon rope in place by pinning it to the grass.

They can also be used to mark distances along the staked rope - the stakes are pre-modeled with the numbers 10, 15, 20, 25, and 30. A blank stake is also included.(and can be found on OnShape here),and can be modeled to add your own number, or printed blank and written on with a Sharpie.

I made these specifically to hold down and mark distances along a rope I use to practice putting around my disc golf basket. I tie one end of the rope to the pole supporting the basket, and set these stakes every five feet along the rope.

Aside from my intended use, I could see these being useful for holding down a rope while marking out landscaping. Or, scaled up a bit, they could be used to hold an irrigation line in place in your garden, while also providing a place to write on to mark your rows.

I printed mine in white Elegoo PLA on a 0.6mm nozzle, and they seem to be plenty strong for sticking into the ground.