Though the golf course management may not contravene any Rule of golf on its own, if a local condition interferes with the proper playing of the game, it may modify a rule with the approval of the USGA.
Local rules are shown on the back of the scorecard and should be read before you start your round. You might find things like identifying particular objects which can be treated as immovable obstructions. Special areas where the operators do not want foot traffic or balls to be hit out of might be designated as an area from where a free drop may be taken.
Some courses have power lines running low across a hole and say what to do if your ball hits one (generally, play another from the same spot without penalty).
Special drop zones might have been set up on certain holes for certain hazards. Special drops might be awarded for the protection of young trees.
If there is habitual temporary wetness, a special procedure can be established.
The meaning and location of stakes marking water hazards and out of bounds may also be described in the local rules section. Note especially if there is an out-of-bounds area within the perimeter of the course. If a hole borders the practice range, expect the range to be marked as out of bounds.
Read the local rules on the back of the scorecard. They are there to help you play better and take care of the course for the golfers who come after you.
My new book, The Golfing Self, is now available at www.therecreationalgolfer.com. It will change everything about the way you play.