Hazard

[Farzin]

QUOTE
All lakes and ditches are defined as water hazards (red and yellow stakes) PENALTY - 1 stroke , drop two club length from point of entry. UNQUOTE
The above quote is printed on the back of score card at a local golf course. However there is no stakes at the golf course around the dithches that are crossing the fairway or along the fairway on the rough sides of the fairway.. what rule does apply to a ball that falls in the ditches, considering there is no stakes, but the score card says ditches are hazard.
the following is the PGA definition of hazard
QUOTE
Definitions
A "water hazard" is any sea, lake, pond, river, ditch, surface drainage ditch or other open water course (whether or not containing water) and anything of a similar nature.

All ground or water within the margin of a water hazard is part of the water hazard
Note 1: Water hazards (other than lateral water hazards) should be defined by yellow stakes or lines.
Note 1: Lateral water hazards should be defined by red stakes or lines.
..UNQUOTE
please note that the word "should" is used rather than the word "must" for defining water hazard with stakes.

Source: http://golf.about.com/cs/rulesofgolf/a/rule26.htm