Anytime you dig, you should technically call for “locates,” which is a free service. A company will then come out and mark all underground utilities for the properties in question (where work is planned).It always makes me think some massive construction project is forthcoming, where the roads and sidewalks will all get dug up. Fortunately, usually nothing happens. Which makes why they had someone go out and mark everything up.
Even if you’re just planting a tree, it’s not a bad idea. Not only will you not put yourself at risk, but you might change your mind about putting that tree right on top of one of your underground services.
I’ve never seen so much width marked for a comm line though.