I figured they were post count markers.
I Managed and was chief everything guy for 18 years in a 100 unit park.
There is not much I can't say I have repaired or installed...LOL
Sold the park, now operate a powersports shop for the last 23yrs..
Sell previously enjoyed toys....Bike, Boats, Snowmobiles, and RV's
And sevice and repair all of the above.