Jason is right. I used to live is district with such a designation. The houses were, for example, given plaques saying what year your house was built, and perhaps there were certain more restrictive rules such as not being able to tear them down, or add a 2nd floor, or other such things, without first passing through a "committee" decision or whatever. But no, it didn't extend down to silly stuff like if you can or can't dig up your own garden, etc..... At least that's the way it was for where I was at.
I would disagree with Dirty-Deed's advice to go asking. The problem with this becomes, that you might actually get someone to tell you "no", when no real rule exists. Some hyper-sensitive or mis-informed desk clerk can merely try to morph something else to apply to your question (ie.: "no altering the home" or whatever) and say whatever he/she thinks. When truth be told, no one would probably have cared or noticed. If you are really this skittish, you can look up rules for yourself (available on-line perhaps? Or each home-owner has a list with his deed? etc...). If it is silent on the issue, then so be it. But no need to go asking, as if you were asking their "permission" or whatever. If, as you say, the property is private property, no one can stop you from metal detecting in your own front yard.