Can I dig?

That is not from ATT but from a locater service such as calling 811.

It identify existing wiring, not the depth of wiring.

Thank you for your response. Can you tell me what it may mean with regard to my situation?

It really depends on where it is located in your yard. Is it running across the front of the porch will into your yard or is it running across your yard in an easement near a sidewalk or the street? When you said the spray paint was "maybe 4 ft wide" that is the normal easement area width.

A picture of the area in relation to your porch / full front yard would help but since it was marked by "DigSafeIllinois.com" you should not dig below the marked area unless you want to be responsible for any repairs or replacements.

ATT/D - is for local AT&T Distribution cable(s) that could be passing through your yard or provide service directly to your residence.

Dave

It's next to my porch, right in the middle -- I assume the cable runs perpendicular from the house to the street, but I was going to leave the rest of the yard in grass. It would be easy to avoid a cable's width while digging, but avoiding the full span of the spray-paint makes putting in a hedge seem tricky.

One flag tells you nothing, there has to be at the very least two so you don't have to "assume" which way the cable runs. I'd request they come back and give you a better idea of what's there.

That's the reason I came here -- to request clarification. Does AT&T not monitor these forums? What is the point otherwise? There's no phone number or email provided on the only flag for me to contact them: only an unreadable blotch of spray paint. Protecting their lines seems to be far more important to me than it is to this company.

ATT does not provide location services, that is the function of your local 811.

This forum is for users to connect with other users. 

ATT has a buried wire center, for wires that need to be buried. On most markets outside of Bell South 9 states the burial is performed by local contractors.

Locator services (811) generally place a tone on the line and use a device similar to metal detector to find buried services and use flags and paint to mark what they find. 

As you know something is underneath and desire more info would require hand digging as the line may be a few inches to several feet below ground level. 

Basically, the flag tells you there's something there.  What you need to do at this point is carefully excavate around said flag until you find the cable... or you dig as deep as you intend (plus another inch or two) several feet across the front of your home and you do not find any cable.  When you find said cable, note its location--maybe wrap colorful tape around it to make it very visible--and do your work avoiding pulling, cutting or crushing it.  You probably don't want to plant a bush right over it (for multiple reasons).  As you finish up your work, lay it as far down in the loose soil as you can.  

This is sort of assuming that the cable runs to the house from the street.  If you dig and find that the cable runs across your yard at that point, it will make your work harder to avoid it over a larger area and you still need to avoid planting right over it.  I'd be very surprised that this is the case, though you may very well find the cable runs along the wall to go to the corner of the home.  Look for the NID on the side of the home to tell you which way it likely runs.

Plus, the ONE flag says is a distribution cable, which is hard to believe that far from the sidewalk and that close to the house. Than again what it says may only mean that's what the locating service had in the way of flags. Get them back out and tell them you need to know the route the cable runs. I suppose it could be a drop that feeds the house and the porch wasn't there when it was initially ran.